> On Jun 19, 2016, at 3:50 AM, Torquil Macdonald Sørensen <[email protected]> > wrote: > > Hi! > > I have solved a PDE generalized eigenproblem (A*v = lambda*B*v) in > libmesh, but I would like to do some linear algebra computations that > involves the A and B matrices, some of the eigenvectors v, as well as > A2/B2-matrices that arise from a different type of discretization of the > same PDE. > > I guess I will probably have to create a second EigenSystem
Or derive from EigenSystem and implement something more specialized to your specific app? > in order to > create A2 and B2, but how can I perform linear algebra computations > involving all of these matrices and vectors? Look at the SparseMatrix and NumericVector interfaces. Everything you need should be available, if not we can certainly add something. > Are there any known libmesh examples where computations such as v^T*A2*v > are done, where v is an eigenvector from the A/B generalized > eigenproblem, and A2 comes from a different eigenproblem? Sparse matrix-vector and vector-vector products are available in the interfaces I mentioned. > Is it possible to get access to A/B/v/A2/B2 as PETSc-objects that can be > manipulated freely using PETSc functions? Yes, but I'd just stick to the generic SparseMatrix interface if possible. ------------------------------------------------------------------------------ What NetFlow Analyzer can do for you? Monitors network bandwidth and traffic patterns at an interface-level. Reveals which users, apps, and protocols are consuming the most bandwidth. Provides multi-vendor support for NetFlow, J-Flow, sFlow and other flows. Make informed decisions using capacity planning reports. http://sdm.link/zohomanageengine _______________________________________________ Libmesh-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/libmesh-users
