[dune-fem] Lagrange DG extract points

[Agnese, Marco]

Hi Andreas,
thank you for the suggestion but I don't think is possible to use it in my case. 

Indeed my analytical function depends on 3 parameters (x_global,t,entity). 
I need the entity information because I have a coefficient which depends on the physical ID of the element.

It is very inefficient to find the entity information from the x_global. 
Do you think that it is still possible to adapt in some way the example to my specific case?

Cheers,
Marco