RE: [Libmesh-devel] Refinement assumptions

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

On Wed, 11 May 2005, KIRK, BENJAMIN (JSC-EG) (NASA) wrote:

> That is true.  When the intersection of a parent side and child side is not
> empty then the two sides are the same number.

Okay, then, my only remaining question is "when is the intersection of
a parent side and child side not empty?"

Yeah, I wish I were kidding.  But I'd like to be able to compute this
information (which I'll be adding as Elem::is_child_on_edge() and
Elem::is_child_on_side() ) in advance; the easy implementation of
building both sides and checking for common nodes would add yet more
time to a coarsening projection that already looks unpleasantly slow.

Would I guess right in assuming that child i shares local vertex
number i with its parent?  If that's true, it's enough information for
me to implement all the Tri/Quad/Hex is_child_on_* functions easily,
and I can puzzle through the remaining Tet and Pyramid children from
the embedding matrices.

Thanks,
---
Roy