That is awesome. That solves my problem. Thanks --Junchao Zhang
On Fri, Jan 22, 2016 at 9:52 AM, Paul T. Bauman <ptbau...@gmail.com> wrote: > You need to make sure you call System::reinit_constraints ( > http://libmesh.github.io/doxygen/classlibMesh_1_1System.html#ad12672358a8e9796a42bd7f42888c54f) > after your update to update the Dirchlet boundary condition if it depends > on time. > > On Fri, Jan 22, 2016 at 10:45 AM, Junchao Zhang <junchao.zh...@gmail.com> > wrote: > >> I added DirichletBoundary to adaptivity_ex2, but I found I couldn't get >> correct Fe at time 1 (i.e, system.time = 0+dt). I am not sure it is a >> limit >> of libmesh, or my understanding is wrong. >> adaptivity_ex2 is a transient problem. "the initial condition will be >> taken >> as the exact solution at time 0, as will the Dirichlet boundary conditions >> at time t." The outline of the code is: >> >> 1. system.time = 0; >> 2. Create a DirichletBoundary object and add it to equation_system; >> 3. equation_systems.init (); // Init solution and Dirichlet constrains >> at time 0 >> 4. >> 5. for each time step { >> 6. system.time += dt; >> 7. *system.old_local_solution = *system.current_local_solution; >> 8. for each refinement step { >> 9. Ke += ... >> 10. Fe += ...system.old_solution()... // Need solution computed at >> time 0 >> 11. heterogenously_constrain_element_matrix_and_vector; // Uses >> constraints computed at time 0, but should use constraints computed at >> time >> 1 >> 12. Add Ke, Fe to global matrix and vector; >> 13. Solve the system; >> 14. equation_systems.reinit (); >> 15. } >> 16. } >> >> Suppose the code runs straight from line 1 to line 11, at line 11, what we >> use are wrong constraints computed at time 0. Actually, we should use >> constraints >> of time 1, which are not computed yet. >> I tried to rearrange the code, but I found I could not make it, since I >> could not use solution of time 0 and constraints of time 1 at line 10 and >> 11 at the same time. >> >> Any thoughts? >> >> >> --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
