Assemble the Uexact vector, then compute the difference e = U - Uexact. You can also refer to error_estimation/exact_solution.h, but I believe that's used for computing L2 or H1 error, not an arbitrary energy norm.
David On Tue, Jan 19, 2016 at 5:04 PM, Junchao Zhang <junchao.zh...@gmail.com> wrote: > How to get e = U - Uex? Is there a libmesh interface for that? > > --Junchao Zhang > > On Tue, Jan 19, 2016 at 3:57 PM, David Knezevic < > david.kneze...@akselos.com> wrote: > >> Assuming you've already assembled K, so you can just do a matvec >> (SparseMatrix::vector_mult) followed by a dot product (NumericVector::dot). >> >> David >> >> >> >> On Tue, Jan 19, 2016 at 4:53 PM, Junchao Zhang <junchao.zh...@gmail.com> >> wrote: >> >>> Hello, >>> I want to compute e^TKe as a measure of the error of a solution. Here >>> e = >>> U - Uex, supposing I know the analytic answer to the PDE. >>> How can I do it in libmesh? Is there an example? >>> Thank you. >>> >>> --Junchao Zhang >>> >>> ------------------------------------------------------------------------------ >>> Site24x7 APM Insight: Get Deep Visibility into Application Performance >>> APM + Mobile APM + RUM: Monitor 3 App instances at just $35/Month >>> Monitor end-to-end web transactions and take corrective actions now >>> Troubleshoot faster and improve end-user experience. Signup Now! >>> http://pubads.g.doubleclick.net/gampad/clk?id=267308311&iu=/4140 >>> _______________________________________________ >>> Libmesh-users mailing list >>> Libmesh-users@lists.sourceforge.net >>> https://lists.sourceforge.net/lists/listinfo/libmesh-users >>> >> >> > ------------------------------------------------------------------------------ Site24x7 APM Insight: Get Deep Visibility into Application Performance APM + Mobile APM + RUM: Monitor 3 App instances at just $35/Month Monitor end-to-end web transactions and take corrective actions now Troubleshoot faster and improve end-user experience. Signup Now! http://pubads.g.doubleclick.net/gampad/clk?id=267308311&iu=/4140 _______________________________________________ Libmesh-users mailing list Libmesh-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/libmesh-users
