dolfin team mailing list archive

["Garth N. Wells" <gnw20@xxxxxxxxx>]

Johan Hake wrote:
> On Wednesday 19 August 2009 17:29:52 Garth N. Wells wrote:
> > What's going on behind the scene when I copy one vector to another in
> > PyDOLFIN using
> >
> >      u0.vector()[:] = u.vector()[:]
>
> When I add:
>
> u2 = Function(V)
> u2.vector()[:] = u.vector()[:]
>
> # Plot solution
> plot(u2)
>
> In a the Poisson demo it works fine.

In parallel?

> This type of slice only uses the assignment operator. 

The GenericVector assignment operator?

I delved into the problem and the program ends up in the function 
_compare_vector_with_vector from dolfin_la_get_set_items.i. It uses 
GenericVector::get and GenericVector::set. These need to be used with 
caution in parallel.

Garth

Other slices might not
> work. Have not checked.
>
> Johan
>
> > ? The issue is that it doesn't work in parallel.
> >
> > Garth
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