From: Roy Stogner <roystgnr@ic...>  20050725 22:27:39

On Mon, 25 Jul 2005, Michael Povolotskyi wrote: > Dear libmesh developers, > I have a question about the hanging nodes problem. > > As far as I know, it is possible to apply DOF constraints in order to have > continuous solution with hanging nodes. > Is it possible to insure continuous derivative of the solution? Even without hanging nodes, it's not possible to ensure C1 continuity of your function spaces without using finite elements specifically designed for it  ensuring interelement continuity requires a lot of derivativebased degrees of freedom on element sides. I'm afraid that the only such elements which exist in libmesh right now are 1D cubics, 2D quadratic reduced CloughTocher composite triangles, and 2D cubic CloughTocher composite triangles. If there are any others you've got in mind, I'd appreciate help adding them  the only additions on my own todo list are cubic tensor products (which won't work on noncartesian meshes) and quintic composite tetrahedra, and it'll be a while before I've got either implemented and debugged.  Roy Stogner 