Re: [Libmesh-devel] isEvaluable on DOFs?

[Roy S. <roy...@ic...>]

On Thu, 1 Dec 2016, Cody Permann wrote:

> I'm starting to use the new Elem::isEvaluable() method available in libMesh. It seems like it would be handy to promote this method up to
> DofObject though so it could be used with Node. If I understand correctly, a node "should" be evaluable if it's attached to any element that's
> evaluable so this method could be implemented rather easily. Does this sound reasonable?

The bad news is that getting a list of all the elements attached to a
Node is surprisingly hard - there's basically no way to do it without
a PointLocator, and no way to do it in O(1) time.

The good news is that we don't need a list of all the elements sharing
the node, just a list of all the DoF indices hosted on the node.  My
inclination would be to add an extra overload to DofMap::dof_indices()
to grab those, and then the new DofMap::is_evaluable() implementation
would be the exact same as the old DofMap::is_evaluable(); we could
actually just make them two instantiations of the same templated
function.
---
Roy