Hi, deal.ii developers and users Recently, I get this question as been mentioned in subject.
I have a saddle point problem on hand. The system of vector-valued PDEs is non-linear. I implement the solver with Newton iteration without line search. And I also need to set up a specific initial configuration for iteration. Here comes the question, I don't have clear idea how to access and write down a specific value on the 0-th solution vector according to every Dof's geometric location on grid. Let's say we have a 3-components vector-valued unknown. Geometry domain is 2 * 2 * 2 size cube. I want to set Dofs, which are inside ball x^2+y^2+z^2=1, to be (1, 1, 1) at every vertex. While the rest of Dofs of the cube to be (1,0,0) at very vertex. I went through docs of DoFHandler, DoFTools, ComponentMask and CellAccessor. Unfortunately, I only figured out that I can access certain DoFs in solution vector by loop over IndexSet, which is generated by DoFTools::extract_dofs(DofHandler., ComponentMask). I still no idea how to control the access through geometric information i.g., vertex's coordinates. Is there any clue or idea how this could be done? Best, Timo -- 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. To view this discussion on the web visit https://groups.google.com/d/msgid/dealii/d52006f4-e1e7-4a92-b627-4c912baae136n%40googlegroups.com.
