dolfin team mailing list archive

[Ivo Conradi <I.M.Conradi@xxxxxxxxxxxxxxxxxx>]

Thanks for the responses. I added some periodicity data to the mesh
object and got the FEM to manipulate the matrix and vector (with
GenericMatrix::get/set) to apply the periodic bc's.  This works, but
unfortunately this is not very fast, because I don't use any sparsity
information. 

This is why I would like to know if it is possible to add a getRow()
function to GenericMatrix.  As far as I know the derived classes
support it and it would help me speed up things, but I have been unable
to get it working.

Any comments would be highly appreciated.

regards,

Ivo

On Mon, Nov 13, 2006 at 09:28:07AM +0100, Johan Hoffman wrote:
> You may for example apply your periodic bc by identifying "master and
> slave" dofs on the two (if periodic in one direction) periodic boundaries;
> so that when assembling, all contribution to the slave dofs are added to
> the corresponding master dofs, and the slave dofs are then identified with
> the master dofs (in the simplest way by using 1 and -1 in the rows of the
> slave dofs; maybe not that pretty, but it works in many cases...).