dolfin team mailing list archive

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

On 25/01/11 15:26, Joachim Berdal Haga wrote:
> 
> 
> On 25 January 2011 16:15, Garth N. Wells <gnw20@xxxxxxxxx
> <mailto:gnw20@xxxxxxxxx>> wrote:
> 
>     On 25/01/11 15:06, Joachim Berdal Haga wrote:
>     >     > It seems that this is only implemented for rows, not for
>     columns.
>     >
>     >     Do you mean GenericMatrix::local_range? It takes a dim argument,
>     >
>     >      std::pair<uint, uint> GenericMatrix::local_range(uint dim);
>     >
>     >
>     > Yes, but:
>     >
>     >    if (dim == 1)
>     >     error("Cannot compute columns range for Epetra matrices.");
>     >
>     > ...
>     >
>     >       if (dim == 1)
>     >         error("Cannot compute columns range for PETSc matrices.");
>     >
> 
>     OK.
> 
>     We need to look at this more carefully. PETSc provides the function
> 
>      MatGetVecs(Mat mat,Vec *right,Vec *left)
> 
>     for getting vectors with a compatible layout, which might be helpful.
> 
> 
>  Very helpful, yes. And epetra matrices has a RowMatrixColMap methods
> which can be used. Do you think it's worth it to add
> create_{left,right}_vector to the GenericMatrix interface as I suggested
> initially?
> 

I'd prefer to take a closer look before committing.

It's good to have another parallel tester!

Garth

> -j.
>