On Wed, 16 Dec 2015, Harshad Sahasrabudhe wrote: > Thanks. Yes, my goal is to have a non-diagonal mass matrix. I want > to take the easiest path possible for doing that using LibMesh. By > mass lumping with a Lagrange basis, do you mean having cell centered > finite volume using a 0th order Lagrange basis in finite element?
No, even simpler a change than that: Use Lagrange finite elements, but instead of approximating your integrals with Gaussian quadrature, approximate them with nodal quadrature (QTrap in libMesh IIRC). Each quadrature point falls on a node, and only one Lagrange shape function is non-zero at that node, so you only get contributions to the equation for that shape function so your mass matrix is diagonal. --- Roy ------------------------------------------------------------------------------ _______________________________________________ Libmesh-users mailing list Libmesh-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/libmesh-users
