dolfin team mailing list archive

[Johan Hake <hake.dev@xxxxxxxxx>]

Any comment on this?

Basically we need another constructor which generates a shallow copy of
a Function, which also has access to the original Function.

Johan

On 02/21/2013 07:08 PM, Johan Hake wrote:
> Hello!
> 
> To fix:
> 
> [child().child() fails for Function and FunctionSpaces in Python]
> https://bugs.launchpad.net/bugs/1130354
> 
> we need to add a way of shallow copy a Function. For now we have used:
> 
> Function(boost::shared_ptr<const FunctionSpace> V,
>          boost::shared_ptr<GenericVector> x);
> 
> Which create a new Function with a shared FunctionSpace and
> GenericVector. The problem is that there is no way of bringing
> Hierarchical data to the new Function as it is not passed through the
> constructor.
> 
> We would need something like:
> 
> Function(boost::shared_ptr<const Function> u);
> 
> which is interpreted as a shallow copy.
> 
> We could then map this to:
> 
>   Function._shallow_copy()
> 
> and
> 
>   Function(const Function& u);
> 
> to
> 
>   Function._deep_copy()
> 
> in the Python interface. Then we add:
> 
>   Function.
> 
>   def copy(self, deepcopy=True):
>      if deepcopy:
>         return self._deep_copy()
>      else:
>         return self._shallow_copy()
> 
> Any objections to adding:
> 
>   Function(boost::shared_ptr<const Function> u);
> 
> as a shallow copy constructor?
> 
> If so we could maybe remove:
> 
>    Function(boost::shared_ptr<const FunctionSpace> V,
>             boost::shared_ptr<GenericVector> x);
> 
> as I think we added it so we could create a shallow copy in the Python
> interface.
> 
> Johan
>