Hi Roy, I am into creating a FEMContext object to evaluate the solution at any (x,y).
I saw an example in "fem_system/fem_system_ex1" but could not figure out exactly what is going on. Navigating in the discussion list, I found the thread https://sourceforge.net/p/libmesh/mailman/message/25983435/ where Derek says: > Secondly... If this sounds like a lot of work.... It kind of is. > That's why the MeshFunction object exists... Just initialize it with > your solution and EquationSystems and it will do all of the above for > you... What is the tradeoff of using MeshFunction? It seems that the solution you proposed (building a FEMContext) will help me on other stuff in the future, as the problem complexity grows. Can you point out some examples or discussion threads on that? Any hint will be really helpful. Thanks, Renato On Thu, Aug 10, 2017 at 7:29 PM, Renato Poli <rebp...@gmail.com> wrote: > >> But if you're writing GUI code you're probably stuck calling those > methods from a single process, right? > True - at least that is how I thought it through. > Graphical visualization is essential in this effort ... > > >> If you need to, then that's when to do it. > Good to hear I am not completely lost. > > Thanks. This thread was really helpful. > > Regards, > Renato > > On Thu, Aug 10, 2017 at 4:34 PM, Roy Stogner <royst...@ices.utexas.edu> > wrote: > >> >> >> On Thu, 10 Aug 2017, Renato Poli wrote: >> >> >> If you want remote DoF values in parallel you have to sync or >>> serialize them yourself. >>> >> >> If I understood, this serialization should be done upfront once, >>> before iterating through the elements. >>> >> >> Ideally, this serialization is done *never*. But if you're writing >> GUI code you're probably stuck calling those methods from a single >> process, right? >> >> As in introduction_ex4, it seems that the parallelization is >>> confined in "solve", which returns only after the job is all done. >>> >> >> Nope. When a range is set up from mesh.active_local_elements_begin() >> to _end(), the "local" part of that means you're only iterating over >> elements which are local to the current processor. So no >> serialization is ever done. Later in the assembly, the "add_matrix" >> and "add_vector" calls are essentially the first halves of parallel >> actions - they queue up values to be accumulated when the solver >> closes the parallel matrix and vector later. >> >> I should then serialize to the master node just after the "solve". >>> Is that right? >>> >> >> If you need to, then that's when to do it. >> --- >> Roy >> > > ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot _______________________________________________ Libmesh-users mailing list Libmesh-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/libmesh-users
