Re: [Axiom-developer] Re: doyen

[Alejandro Jakubi]

Tim, Alfredo, CY

> The address@hidden mailing list is the best forum
> for this discussion. I've taken the liberty of copying your questions
> and comments to the list so we can all contribute.

> Please
> subscribe to this list so you can be up to date with the project.

I have subscribed, but I have set the filter to select those posts with the
subject doyen.

> for particular conferences. Speakers can develop literate programs
> (paper text and program code combined, ala Knuth) that run on the

The expression "literate program" is fine for a program combined with its
documentation, the subject being the program. But a paper, understood as a
piece of scientific research, should be more than the documentation of some
code. So, I beleive, an expression like "coded paper" or something equivalent
would be more suitable for a paper combined with any code that was used,
even though the same or similar techniques were used to create and process
documents in either case.

> necessary to support the software requirements of various disciplines
> such as math or physics. (Since each DoyenCD is specific to a field


> I've had discussions with Jurgen Gerhard of Maplesoft about the
> licensing issue.

An "e" seems to be missing in the cc address address@hidden

> problem. Perhaps their new licensing scheme will allow us to create
> "custom" Doyen CDs that have keys which are registered to conference
> attendees. That would complicate the Doyen CD production but might
> make it acceptable to Maple.

Flexlm allows for limited time licences. So, licences for the period of a
conference would be like those for a limited period demo, I think. It would
require individual network activation though.

> The issue here is broader than any one particular system. I've
> proposed a project called the Computer Algebra Test Suite (CATS) which
> would create a taxonomy similiar to the NIST numerical math standard.

It sounds like the continuation of the work by Michael Wester "A Review of CAS
Mathematical Capabilities" and related reviews.

Even when I would find very useful to have such a CAS standard, I wonder how
far CAS could be standarized. I may be wrong, but I have the impression that
symbolic math is a much more diversified field than numeric math.

Many issues could be raised here. They include:

a. Neutrality. Sometimes those comparing reviews were criticized as being
designed to favor a given system.

b. Universality. The coverage of the tests will much depend on the "agenda" of
the designers of the suite. But the interests of different groups of users may
differ widely. Indeed, the subjects of interest for physicists are quite
different to those of interest for mathematicians, and they are largely
missing in open source/free CAS.

> Systems could be compared,

For physicists, the usual comparison is Mathematica vs Maple. It has been so 
since
the early '90s and I do not see any sign of change in the near future.

> One doesn't always want to achieve that.  The first question to be asked
> should be "is this new behavior wrong, or was the old behavior wrong?"  (In
> more subtle cases - obviously a crash is wrong.)  It is possible the 2006
> result was wrong.  That's actually an objection I have heard in the past to

Correction is one issue and reproducibility is another one.

By the way, one of my interests in looking at different CAS is checking results
in for errors...

But the need of reproducibility is basic in science and the publication of
scientific results needs dating to set the record. By merging papers and code,
the need of reproducibility of code results is made explicit. There are many
possible sources of errors in a paper, and errors arising in bugs of the CAS
that could have been used for calculations is just one of them. Whatever
happens after publication, eg whether the bug is detected and patched, the
calculations are made again, a corrected version of the paper is published,
etc, is a different issue. Anybody should be able to able to reproduce a given
result as it was published, right or wrong.

As I observe in Maple, along the late 12 years, there has been changes of the
most diverse nature in this system. They include, patched or obsoleted
libraries, changes in the language and in the format of the worksheet. Just
observe that several of the Maple entries in the Rosetta document are
currently (ie for Maple 10) obsolete. In cases that syntax is no longer
working. And it is just a few years since it was written!

CAS, when successful, are long term projects. This means that different
generations of developers would work along the time, each one with its own
preferences. What is better, whether a development following rigid rules or
accommodating to circumstances, seems to be a matter of taste. The later model
can be easily observed in Maple that seems as an accumulation of "geological
strata" with commands working in very different ways, depending on its era of
development.

> Open source software in general can track changes to the underlying systems,
> and a behavior change from one version to the next would be regarded as a
> bug. (Or maybe a fixed bug, depending.)  New versions would contain patches
> to new systems.

Most open source projects are rather new. It will be interesting to see
whether they endure decades and how do they evolve. In particular whether a
Axiom 2036 will handle correctly the a document written with the syntax of
Axiom 2006.

The evolution of the TeX system up to now, where almost any document written
in the past can be processed today as it was at its time, gives hope that this
example could be followed.

> Well, it depends on what you wanted to find inside Doyen :-). The lack of
> maybe

> FWIW, I think it is safe to say that Axiom and Maxima represent the two most
> powerful general purpose open source computer algebra systems available.

I have already Axiom and Maxima installed both in Windows and Linux (FC4 and
Debian Sarge). Curiosity, the possibility of looking at diverse systems
without the need to download and install them one by one, was my main
interest. In particular the posibility to try the latest versions. This is
important for me as ports to Windows may not be available or correspond to old
versions. And I prefer much Debian to Fedora, but stable versions may also be
old.

> general problem.  Why shouldn't it be possible to do all of this work inside
> one larger, robust, and powerful framework?  Then each new algorithm and tool
> would be immediately available for use in any new work.

Agreed. The utopia of the universal system is very nice!

> Axiom's design gives me hope for this goal - it appears to be designed
> generally enough that it can scale.  But there are many years of work ahead
> to make it a well documented and robust system.

But note. The usefulness of a system may depend on factors rather independent
of the quality of design. For instance the size and diversity of its community
of users. Quite frequently I have found that the Maple package that makes the
job was contributed by a user...

> One thing that we have lack is feedback, like yours, proposing things
> to be added to Doyen.

OK, some feedback:

1. I could not run properly doyen04262005 on my machine at home because it
produced some ammount of cloop readerror messages. It run fine on an older
machine at the office, though. Sadly, there is no md5 file to check the iso
file. Anyway, I have found that this Knoppix version boots on that old PC much
faster than the FC3 based doyen081306 on the faster machine. It takes over
five minutes. Too much!

2. I have played a little bit with the doyen wiki sandbox, executing a few
Axiom and Maxima commands, and writing some LaTeX equations. I think that this
is all that the tutorial shows that can be done right now. For this little
test, I have found the display of LaTeX and Axiom output formulas is fine,
except for roots. I would prefer fractional exponents as in $(a^2)^(3/5)$. I
find confusing a root sign with 2,3 and 5 located in three different places
around the $a$. Maxima output, on the other hand, looks very bad with those $
signs.

3. I have tried an Axiom plot but got an error message:

draw(sin(x),x=0..%pi)
   >> System error:
   Cannot create the file /tmp/gazonk0.fn.

Maxima plots do not work as gnuplot is missing. Indeed it should be added.

4. I have observed that this implementation is based on a web browser as GUI,
using png files for displaying math. I wonder why not using mathml instead.
One disadvantage of the current approach is the generation of png litter.

I have also read the Sage documentation (I will try to download it later on).
What I have understood is that they use javascript instead, but not how.

And yet another approach is that of TeXmacs. Indeed, I have found that
TeXmacs-Axiom works fine under Windows and Linux, except for ploting. So, I
beleive that it is an application that fits naturally here. In fact, I was also
expecting to find it inside...

5. One subproduct say, of your development is that the doyen CD seems to have
a fairly complete TeX installation. This is missing, in the live CDs that I
have seen up to now. It could be useful eg in case of needing a working TeX
system where it is not available.

6. The non uniform default background for the console window is bothersome to
my taste. I change it every time.

7. The Session Saver says that it has saved successfully the file
doyenWikiDB.tar.gz in /home/doyen but it saves nothing.

8. Sooner or later, the accumulation of material will force a move to a DVD as
media, but before of that, I think that there are some packages that could be
safely removed without affecting the functionality of this distro as a
scientific platform.

9. My USB drive is not mounted at boot nor any entry for it is made in
/etc/fstab. Anyway, I can mount it later on.



Regards, Alejandro Jakubi