Re: [Axiom-math] Axiom: Printing multiple variables in axiom.

[Bill Page]

On 11/12/07, Constantine Frangos wrote:
>
> On Monday 12 November 2007 08:45, Martin Rubey wrote:
> > Bill Page writes:
> > > Why do you write 'unparse(y::INFORM)' ? Do you mean you literally
> > > want to output a ' * ' character for multiplication? If so, I think there
> > > must be a better way than this ...
> >
> > I guess that Constantine also wants 1-dimensional output. I.e., x^2
> > instead of
> >
> >  2
> > x
> >
> > But I'm not sure.
>
>
> Yes, that's correct. It would be helpful to obtain one-dimensional
> output (ala Maxima with display2d : false) that can be pasted as
> is, in other axiom functions, and run correctly.
>

Ok, I understand.

>
> >
> > Of course, the real solution would be to overwrite the coercion
> > to OutputForm in Expression.  But that's probably too much to
> > ask for from Constantine, and I don't have the time to play around
> > with that.
> >
> ...
> I was thinking of defining
>
> DCOS(x) == cos(x)
> DSIN(x) == sin(x)
> etc.
>

After looking at the Axiom source code I see that 'unparse' is
actually internally calling functions which convert an expression in
Axiom form to Fortran form. The necessary code is found here:

http://wiki.axiom-developer.org/axiom--test--1/src/algebra/MkfuncSpad
http://wiki.axiom-developer.org/axiom--test--1/src/interp/NewfortBoot
http://wiki.axiom-developer.org/axiom--test--1/src/interp/FormatBoot

But it isn't really necessary for you to understand all that. Here is
a distillation of the important parts into a fairly simple function
that I think probably does what you want:

(1) -> output1d(e)== _
  message( _
    concat map(string,destruct _
      fortranCleanUp( _
        exp2Fort1( _
          exp2FortOptimize( _
            outputTran(e::INFORM)$Lisp _
          )$Lisp _
        )$Lisp _
      )$Lisp _
    ) _
  )$OutputForm
                                                   Type: Void
(2) -> output1d(cos(x2) + 2*x1)
   Compiling function output1d with type Expression Integer ->
      OutputForm
`-mcpu=' is deprecated. Use `-mtune=' or '-march=' instead.

   (2)  cos(x2)+2*x1
                                                   Type: OutputForm
(3) ->

If you would like an explanation of how this works, just ask.

Regards,
Bill Page.