[1] 
P. Bastian, M. Droske, C. Engwer, R. Klöfkorn, T. Neubauer, M. Ohlberger,
and M. Rumpf.
Towards a unified framework for scientific computing.
In R. Kornhuber, R. Hoppe, J. Périaux, O. Pironneau, O. Widlund,
and J. Xu, editors, 15th International Conference on Domain
Decomposition Methods, Vol. 40, Lecture notes in Computational Science and
Engineering, 2004. [ bib  .pdf 1 ] Most finite element, or finite volume software is built around a fixed mesh data structure. Therefore, each software package can only be used efficiently for a relatively narrow class of applications. For example, implementations supporting unstructured meshes allow the approximation of complex geometries but are in gen eral much slower and require more memory than implementations using structured meshes. In this paper we show how a generic mesh interface can be defined such that one algorithm, e. g. a discretization scheme, works on different mesh implementa tions. For a cell centered finite volume scheme we show that the same algorithm runs thirty times faster on a structured mesh implementation than on an unstruc tured mesh and is only four times slower than a nongeneric version for a structured mesh. The generic mesh interface is realized within the Distributed Unified Numerics Environment DUNE.
