Re: [Axiom-mail] downloading sources stale?

[Martin Rubey]

Dear Oliver,

I have thought about implementing graph theory in Aldor/Axiom every once and
then, but never actually started a good design.

As you certainly know, there are many many many objects that share structure
with graphs: simplicial complexes, matroids, graphs, digraphs, polytopes, etc.

They are all obviously related, and for many of them it makes sense to have
more than one representation.  Eg,. a polytope can be defined by hyperplanes or
by facets, and the transition from one description to the other is probably NP
hard. :-)

There is a wonderful package mainly for simplicial complexes and polytopes
called "polymake", which you should look at first.  It's design is incredibly
simple and intelligent, and extremely well adapted to the objects listed above.
In fact, I would not really know how to implement this design in Aldor.

However, I did write a wrapper package for making polymake available from
within axiom, so maybe this is of interest to you.  There is a version on
MathAction, and a better version on my local desktop.  But look at polymake
first.

Note that my wrapper really get's the best of both worlds, which is a very
lucky coincidence.  No doubt you can write polymake "clients" (i.e., operate on
polymake objects) in Aldor or SPAD.

Martin