On Mon, 3 Mar 2008, Yujie wrote: > Assuming I know a dof, I want to know which element or point on the > mesh this dof belongs to. How to do it? thanks a lot.
I'm afraid we don't currently have any mapping that lets you do an O(1) lookup in that direction; it's easy to get a global DoF index from an element and a local index, but it's not easy to go the other way around. If you have to do this once, I'd just loop over all elements and all nodes, treat them as DofObjects, loop over all the indices they contain, and stop when you find the one you're looking for. If you have to do this repeatedly, your best bet is to loop through elements and nodes once to construct a mapping (a vector, indexed by global DoF index), then use that mapping for the second and subsequent lookups. Unfortunately, bear in mind that adaptive mesh changes and/or repartitioning would invalidate such a map. Are you still concerned about the interaction between solution projections and localization? I meant to double-check that code this weekend, but haven't gotten around to it yet. I can tell you that I and others have been doing parallel adaptivity without seeing any problems, but if there are subtle errors there we might just not have noticed them yet. --- Roy ------------------------------------------------------------------------- This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ _______________________________________________ Libmesh-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/libmesh-users
