[femlisp-user] Integrating Maxima?

[Nicolas Neuss]

Hello!

I am thinking about improving on polynomial arithmetic and the computation
of quadrature rules and shape functions by adding Maxima to the
CMUCL/Matlisp/Femlisp system.  I have tried a little bit and they have good
and fast calculation of roots of Legendre and Jacobi polynomials with
arbitrary precision (as much as I can see, I hope the digits are correct).
My own code (see algebra;polynom.lisp and discretization;quadrature.lisp)
is rather old (ported from Scheme), not that powerful and is probably
slower (but note that this is an overhead which is only occuring when first
accessing some high-order finite element due to memoization).  An
improvement of this code would be necessary in any case if we want to
handle finite elements of order $p>=6$ seriously.

What do you think?  About one year ago I already loaded Maxima into my Lisp
session which worked fine.  The disadvantage is that it uses another 20MB
of memory (or so).  An alternative might be an external call to Maxima (or
whatever else) to compute the necessary data.  On the other hand, it might
be quite a selling argument for Femlisp to have immediate access to a CAS.

Nicolas.