fenics team mailing list archive

[Johan Jansson <johanjan@xxxxxxxxxxxxxxxx>]

Hi!

I think it's a very nice discussion going on right now, many good
points. I just want to make an addition with a slightly different
perspective.

The application domain we seem to be discussing is scientific
computing on supercomuters, i.e. the target "customer" for Fenics is a
scientist at some lab with a supercomputer.

I think this view is far too limited, but I guess is a symptom of the
particular academic environment most of us live in. PDEs and the need
for discretization appears in computer games, image manipulation,
video processing, computer animation, medical training simulators,
flight simulators, etc. etc. Some of these involve supercomputers, but
some do not. The vision algorithm for a robot probably runs on an
embedded system, but likely involves discretizing a PDE (or at least
could be modeled as one). There's no reason Fenics should not be used
to generate the code for that algorithm.

What is common for all these application domains however is the need
for efficiency and the need for conceptual abstraction (I don't think
a developer of a filter for the Gimp or Photoshop wants to worry about
the details of a finite element solver). I believe Fenics solves both
of these in a very nice way. The input is the form and the element(s),
I can't think of a better abstraction representation, and we can
generate an optimal solver from that completely automatically.

Of course supercomputers are important, and of course parallelism is
important, the embedded system in the robot could probably be parallel
as well. What I'm saying is, let's not tailor Fenics only for
scientists with supercomputers, and in doing so, sabotage Fenics for
other application domains. I believe historically this has been true,
FEM "codes" have been specifically tailored for supercomputers, and
this has limited the spread of the FEM into other domains. If you ask
a typical engineer what the FEM is, he will say that it's a method for
dividing a domain into triangles. As far as I know, the mechanical
engineers at Chalmers don't come into contact with the FEM unless they
specifically choose that track.

We have the opportunity to create a FEM system which can generate
optimal solvers for essentially _all_ domains. We can solve the
accessibility problem of the FEM, which is the complexity explosion of
coefficients and indices once and for all and actually make it
available to normal people (engineers at least), without having to
sacrifice _any_ performance. Or perhaps we should say that "we have
already solved" this problem (with regards to assembly at least), now
it's essentially a question of packaging and further developing it.

  Johan