On Thu, 21 Feb 2013, Manav Bhatia wrote: > L2_LAGRANGE provides the *discontinuous* interpolation using Lagrange > polynomials, so I could use a quad4 and have as high as third order > (currently, and I will be glad to contribute more). However, is there a way > to achieve the same order of *C0 continuous* Lagrange interpolation on > quad4. This would require that the node and edge dofs be consolidated > between elements.
If we stuck with the same isoparametric element paradigm that current LAGRANGE code in libMesh uses, then there's no way to add higher order Lagrange FE support without first adding higher order geometric support, which would be a huge pain in the neck. If we simply mapped the Lagrange bases on to nodes topologically, though, it shouldn't be any harder than writing the high order HIERARCHIC and other bases was, though. We'd still need new geometric elements in a few cases (pyramids, tets, prisms) to give us side nodes, but that's something we've been wanting anyway. I'm not sure how useful people would find that second case, though. In my experience, users who like Lagrange because of its conditioning properties are well outnumbered by users who like Lagrange because it's easy to (sometimes inadvertently) write code which assumes that there's exactly one DoF per variable per Node and that this DoF corresponds to the variable's value at that Point. --- Roy ------------------------------------------------------------------------------ Everyone hates slow websites. So do we. Make your web apps faster with AppDynamics Download AppDynamics Lite for free today: http://p.sf.net/sfu/appdyn_d2d_feb _______________________________________________ Libmesh-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/libmesh-users
