From: Praveen C <cpraveen@gm...>  20130828 13:57:32

Hello I found that TransientExplicitSystem does not have any mass matrix. I wrote my explicit dg code with TransientLinearImplicitSystem and it works. However I end up computing mass matrix every time step and I am not able to solve the matrices at element level. I want to use the TransientExplicitSystem. I want to store the mass matrix as std::vector< DenseMatrix<Real> > with one small mass matrix per element. I can then solve at element level using cholesky_solve function available in DenseMatrix. But where do I store this matrix ? Is it good to store it in the parameters and then access it in the assemble function ? Thanks praveen On Sun, Aug 25, 2013 at 1:38 PM, Praveen C <cpraveen@...> wrote: > Hello > I am writing an explicit RKDG code using libmesh. Having read some > examples, I am thinking of using a TransientExplicitSystem. Is this the > correct approach ? > > Since it is explicit, I only need to assemble mass matrix once. In the > time stepping only the right hand side needs to be assembled. > > Being DG, the mass matrix is block diagonal and can be solved per element. > Its not clear how to do this. Can you point to some existing examples ? > > Also I want to use a multistage RK like the 3stage SSP RK scheme of > ShuOsher. > > Thanks > praveen > 