Re: [Axiom-developer] Re: FeynCalc

[C Y]

--- Bob McElrath <address@hidden> wrote:
> C Y address@hidden wrote:
> > Having Axiom and Maxima versions of Feyncalc would be 
> > really excellent - each system could serve as a check
> > on the accuracy of the other.  Keeping both current would
> > be a bit of work though.
> 
> I would be very, very interested in such a thing, however,
> maintaining three separate codebases would really really suck.

True, but unavoidable if people want the system to work on different
systems.  My hope would be that once the basic ports are complete, as
changes are made to the Mathematica codebase the maintainers of the
Maxima and/or Axiom ports would be able to examine those changes and
take the appropriate steps in their codebases.  Essentially, the
developers doing the new scientific coding would keep doing the
Mathematica thing and the porters could just impliment that in the
other systems.  May or may not be workable - partially it depends on
how actively developed the Feyncalc software is.

> The Mathematica language is the largest I have ever seen.  It
> attempts to be all things, list-based, object-based, functional, 
> patterns, interpreted, compiled, and of course has an extremely 
> large library. Automatic translation from Mathematica may be near 
> impossible.

That was my general impression as well.  I don't advocate automatic
translation.  You never know - perhaps Axiom or Maxima might someday
take over as the primary Feyncalc platform - a Mathematica license as
an entry fee for running Feyncalc can be a hefty price for a physics
department, particularly if they anticipate a lot of users.

> Frankly I think the size of the language makes it poorly suited to 
> almost all tasks, and I hope Axiom and Maxima do not attempt to 
> emulate it.

AFAIK most of Axiom and Maxima's language decisions were made a long
time ago.

> Rather, it may be easier to develop a MMA export mode for
> Axiom/Maxima for the purpose of comparing solutions.  An export 
> mode doesn't need to understand the entire MMA language.  I would 
> like to see a large, cross-system test suite which could be used to 
> validate and improve all systems.  Perhaps this:
>     http://www.math.unm.edu/~wester/cas_review.html
> would be a good starting point.

Something of the sort has been discussed before - I don't know what the
status of it is.  

> In any case, I am extremely interested in this and would like to
> help. I have a pile of Maple code for my use, dealing with 
> supersymmetric lagrangians, feynman rules, etc, and I intend to 
> re-implement it in Axiom or Maxima, and doing so as part of a larger
> package would be ideal.

Sounds interesting!  For what it's worth, there has been some work done
previously translating Maple code to Maxima - can't recall the details
at the moment.

CY


        
                
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