dolfin team mailing list archive

[Johan Hake <hake@xxxxxxxxx>]

On Saturday 17 October 2009 12:32:54 Garth N. Wells wrote:
> Will
> 
>      uh = U[1]
> 
> return a deep or shallow copy of the sub-Function?

To avoid confusion with the ufl interface we have limited the interface for 
SubFunctions in PyDOLFIN to split. split returns a shallow copy by default. 
pass True to split and it will return a deepcopy. In your case it would be:

  uh = U.split()[0]

and

  uh = U.split(True)[0]

operator[] is used when you define forms. We have not yet managed to merge the 
two operations into one.

> Where is the operator [] define for sub-Functions?

The operator you are using is the ufl one, which is defined in 
ufl.exproperators.py. 

Johan