[dune-fem] df.communicate

[Andreas Dedner]

Hi.
A few times now I had the problem that when executing different methods 
communicate on a discrete function was called more then once. For dg 
functions that is not a problem but for lagrange type functions (okay 
functionals) that's a major headache since dofs are added up during 
communication. So an example is in the howto where both the application 
of the operator does a communicate and assembleRHS does one as well. It 
is not that easy to get rid of - in the assembleRHS it could be removed 
but the operator() has to call communicate at the moment otherwise the 
Newton solver wouldn't work (it assumes that the functional is 
completely computed after the call to operator().
I was wondering if others have had that problem (as I said dg people 
once again have an easy life here...). Does someone have an idea of how 
to solve this? A similar problem btw is with the call to clear....
Should we remove clear/communicate from the operators and have the 
solvers, i.e., Newton etc do the corresponding calls?
I am really not quite sure what a good solution is but the situation is 
complicated because it is difficult to keep track of the places where 
clear/communicate might be called....
Andreas