[Axiom-developer] Re: StepThrough (was: Units package)

[Bill Page]

On November 5, 2005 5:09 AM William Sit wrote:
> ...
> On Fri, 4 Nov 2005 09:25:17 -0800 (PST) C Y wrote (Re: StepThrough)
> > --- Martin Rubey <address@hidden> wrote:
> >
> > > Dear Bill, Cliff,
> > >
> > > Clifford, are you still there? I'm not quite sure about
> > > your status now, are you interested in pursuing this project?
> >
> > I am, but probably not immediately - I'm working again on the
> > units package concepts so that will take some time.  My current
> > thought is:
> >
> > 1)  Finish the draft of the "paper/documentation" part of
> > the units and dimensions package,
> > ...
> > 2)  While demolition of 1) is proceeding, I'll dive into the
> > StepThrough issue, which will also be the time when I will
> > really have to come to grips with the design and SPAD
> > programming language of Axiom.  StepThrough is an excellent
> > start because it should be informative, useful, but still
> > relatively elementary (famous last words).  I think it's the
> > usual thing - driving isn't so bad once you know how to drive,
> > and in Axiom's case I need to learn how to drive.
>
> Contrary to what Martin suggests, I think it is a bad idea
> for you to work on two projects simultaneously. StepThrough
> is not a simple issue (I'll comment on this if I can keep up
> with all the discussions).

I would not want to dissuade anyone from working on the issue
of StepThrough and Countable but I tend to agree with William
about this. In some cases, the concept of Countable is relatively
simple (as in the case of Fraction as Martin has shown) but in
other cases it could lead to some rather deep mathematical and
implementation issues. The implications of the category Countable
do seem to affect the Axiom library at a fairly basic level. Of
course these issues are what make the whole subject interesting
and worth pursuing but they may not be the ideal place to start
working with Axiom.

I look forward to reading your thoughts abut this William.

> The coding for UnitsPackage is not as difficult as you think,
> but you should actually take Bill Page's advice and simply
> dive in to get a feel for coding in Axiom (Spad). During all
> the rewriting (you sure will be doing that), you'll learn to
> become fluent in Spad (the compiler version). If you need
> help, lots of people on this board will lend you a hand.
>

We should remember that Martin has already contributed some
working Spad code for units. See:

http://wiki.axiom-developer.org/UnitsAndDimensions

Clifford, (as if you need any more advice ... :) I think a good
place to start would be to understand this code and modify it
(a little at a time) to implement some of the new ideas on units
that you have been thinking and writing about. If you would just
like to try a few things but not have your experiments broadcast
to the email list, you can work here:

http://wiki.axiom-developer.org/SandBoxUnitsAndDimensions

which contains a copy of Martin's original code.

All you have to do is click 'edit' and start making changes
to this code. Clicking 'Preview' allows you to test your
changes and 'Save' with save them for other people to see.
But here in SandBox pages, none of the changes you make
(even when you click 'Save') will result in emails to the
mailing list. So please feel free to treat it as if you
personally own this page.

Regards,
Bill Page.