Yury, first, adaptive multilevel methods only work with discontinuous elements right now.
About your second question: step-16 in the previous versions solved the Neumann problem, but for the equation -Du + u = f The best way to make this work might be to add (a u,v) to the multilevel matrices and use standard components. If a is small enough, it should not destroy convergence. Best, Guido Yury Petrov wrote: >> Hi, >> >> I have two questions: >> 1. Are the multilevel FEM method and the adaptive refinement >> compatible (step-6 + step-16)? >> 2. What needs to be done to adapt tutorial step-16 for Neumann >> boundary conditions? Step-11 suggests using >> DoFTools::extract_boundary_dofs() to set the average boundary value >> to 0, but there is no extract_boundary_dofs() for MGTools class. >> Also, is the average value zeroing necessary in the >> assemble_multigrid() function? >> >> Thank you, >> Yury >> > > _______________________________________________ > _______________________________________________
