On Mon, 10 Jan 2011, Vasilis Vavourakis wrote: > (1) in BEM mostly boundary integrations occur, which means that in 2D > problems only 1D discretization is needed. however, since only Edge elements > are "loaded" to the MeshBase class, when i try to evaluate the normal > vectors to each quadrature point for each boundary (edge) element through > the "get_normals" function then i get an error. one option would be to load > a 2D mesh (of triangles and quadrilaterals) and perform only boundary > integration to all non-neighboring side elements, but this way i would load > into the System the nodes located inside the domain. any ideas on that?
The most flexible idea that jumps to my mind: adding a per-variable flag to identify BEM variables in a System, then querying that in DofMap so as to only assign degrees of freedom to boundary nodes. This would be a difficult feature for a non-experienced libMesh developer to write, though. > (2) the system matrix "A" of the final linear system "A*x=b" in not banded > as in FEM, but full populated... this means that parallelization is not that > easy to implement, right? Our SparseMatrix class would still parallelize large dense matrices; you'd be able to get solutions. The only code change is again in DofMap - the send_list for communication of a BEM variable would need to be full rather than built up from neighbor topology. Efficiency is another question, though; I'm not sure what you'd want to do for preconditioning. --- Roy ------------------------------------------------------------------------------ Gaining the trust of online customers is vital for the success of any company that requires sensitive data to be transmitted over the Web. Learn how to best implement a security strategy that keeps consumers' information secure and instills the confidence they need to proceed with transactions. http://p.sf.net/sfu/oracle-sfdevnl _______________________________________________ Libmesh-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/libmesh-users
