dolfin team mailing list archive

[Mehdi <m.nikbakht@xxxxxxxxxx>]

On Thu, 2010-06-17 at 11:13 +0200, Mehdi wrote:
> Hello,
> 
> We have constant and non-constant versions for Function::Vector(). The
> non-constant one has a check to prevent us having access to non-constant
> vector from a sub-function. 
> 
> GenericVector& Function::vector()
> {
>   // Check that this is not a sub function.
>   if (_vector->size() != _function_space->dofmap().global_dimension())
>   {
>     cout << "Size of vector: " << _vector->size() << endl;
>     cout << "Size of function space: " <<
> _function_space->dofmap().global_dimension() << endl;
>     error("You are attempting to access a non-const vector from a
> sub-Function.");
>   }
>   return *_vector;
> }
> 
> Do we really need to have this check?
> 
> If so, I don't think comparing vector size and global dimension of
> function space is proper check for this purpose.  How this check can be
> improved to just perform what we expect? 

What about using ">" instead of "!=" in the check?

  if (_vector->size() > _function_space->dofmap().global_dimension())

While this prevent us form having access to the underlying non-const
vector of sub function, it allows me to have access to the underlying
vector when the function space is updated.

Yours,
Mehdi

> 
> Since it prevents a user to extract underlying vector and resize it,
> when the underlying function space has been updated because of new
> degrees of freedom.
> 
> Mehdi
> 
> 
> _______________________________________________
> Mailing list: https://launchpad.net/~dolfin
> Post to     : dolfin@xxxxxxxxxxxxxxxxxxx
> Unsubscribe : https://launchpad.net/~dolfin
> More help   : https://help.launchpad.net/ListHelp