Hi Wolfgang, > I would start by asking where the nonzero entries are going to lie. What > kind of operator do you plan on implementing for which you don't know > where the nonzeros are? >
I want to multiply this matrix with a PETSc vector (which is also stored in parallel). When I initialize the PETSc sparsity matrix, I don't know where the nonzeros are. Then I loop over the locally owned cells on each processor, and guadually know for each row of the matrix the locations and values of the nonzeros. Do you mean that I can't directly use the PETSc_sparsity_matrix.add() function to insert nonzero values into the matrix without telling the sparsity pattern the nonzeros locations? *If I have to tell the sparsity pattern where the nonzeros are manually, what are the necessary procedures and functions I should follow and use (since the matrix is not a system matrix, I can't use the DoFTools::make_sparsity_pattern function with an dofhandler as input)?* *For example, for row 0, how can I tell the sparsity pattern the elements at (0,3) and (0,5) arenonzeros? I search the documentation, and find maybe I should use dynamic_spasity_pattern? I am so confused.* -- The deal.II project is located at http://www.dealii.org/ For mailing list/forum options, see https://groups.google.com/d/forum/dealii?hl=en --- You received this message because you are subscribed to the Google Groups "deal.II User Group" group. To unsubscribe from this group and stop receiving emails from it, send an email to dealii+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
