Re: [femlisp-user] Integrating Maxima?

[Mario Mommer]

Hi!

Nicolas Neuss <address@hidden> writes:
> 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 are the issues?

> 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.

Well, Maxima is rather big, as you alredy observed.

Wouldn't it be easier to compute these polynomials and their roots up
to a reasonably high order and to some reasonably good precission, and
just store them away in a file?

Mario.