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["tomtzigt" <tomtzigt@xxxxxxxxxxxxxxxx>]

The way I look at it is as follows: To solve real problems you need the
following pieces:

Geometry
Geometry kernel
Mesher
Assembly
Solver
Data interactivity

The FEniCS effort has mainly focused on assembly. Unfortunately, the
abstractions used in the grid data structure are not as good as they could
be. The DUNE folks have focused on that, so why reinvent the wheel: why not
leverage their skills and work and bring them on board and work towards
similar goals and strengthen the overall effort?

I remember a long discussion last year that didn't go anywhere about the
relationship between FEniCS and Sundance. Clearly, this suggestion between a
DUNE/FEniCS relationship will touch on many of the same topics, most
importantly, that of relevance. IMHO, computational software will only be
relevant if the environment is so good that it allows the practitioners to
ignore the underlying algorithms. Neither FEniCS or DUNE have proven that
yet, but since the grid data structure is so central to all the algorithms
in the mesher and the data interactivity modules, DUNE has a good change of
survival.

I also want to at least bring up the different dynamics that play in
academics vs industry since it can explain the behavior of open source
projects. The focus in academics is to bite of a small piece of the problem
and solve it cleanly and innovatively. This requires isolation from the
overall messy problem. Industry focuses on the economic value of a problem
and isolated solutions have no value. As a consequence, the typical dynamic
of a development group in industry is to rape and pillage anything in sight
that could solve a piece and duct tape it all together. It typically is the
duct tape that provides the added value. And that is my world.
	Except for Johan's work on turbulent flow, I haven't seen a FEniCS
roadmap. So I am not aware of any grid abstractions that you might have in
mind for FEniCS. But from where I am sitting, DUNE looks like a better mouse
trap for working with grids, and since the mesher and data visualization are
both sizable pieces of software, DUNE has some really attractive features. 

Theo

-----Original Message-----
From: fenics-dev-bounces@xxxxxxxxxx [mailto:fenics-dev-bounces@xxxxxxxxxx]
On Behalf Of Anders Logg
Sent: Monday, September 18, 2006 5:20 AM
To: fenics-dev@xxxxxxxxxx
Subject: Re: [FEniCS-dev] DUNE

Yes, I've looked at it. It's one of a handful of projects that have
some similarities with the FEniCS project. But I don't see any
immediate use for it right now, except for possibly using ALUGrid for
adaptive mesh refinement.

/Anders


On Sun, Sep 17, 2006 at 09:54:26AM -0400, tomtzigt wrote:
> Are any of you familiar with the DUNE project? It looks like FEniCS could
> benefit from this effort. I came across them because the key players of
DUNE
> are involved in the BOOST.MPI library review.
> 
>  
> 
> <http://www.dune-project.org>
> 
>  
> 
> 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 general 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 finite
> 
> element discretization scheme, can work efficiently on different mesh
> implementations.
> 
> These ideas have also been extended to vectors and sparse matrices where
> iterative
> 
> solvers can be written in a generic way using the interface. These
components
> are available
> 
> within the "Distributed Unified Numerics Environment" (DUNE).
> 
>  
> 
> It may be beneficial to invite them to Delft in November.
> 
>  
> 
> Theo
> 

> _______________________________________________
> FEniCS-dev mailing list
> FEniCS-dev@xxxxxxxxxx
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