From: Guillaume Marcais <guslist@...>
Date: 2005-06-09T23:18:42+09:00
Subject: Re: [ANN] StringMatrix

On Thu, 2005-06-09 at 09:43 +0900, Gavin Kistner wrote:
> On Jun 8, 2005, at 10:09 AM, Ara.T.Howard wrote:
> > On Wed, 8 Jun 2005, Gavin Kistner wrote:
> >> I decided to write a little Ruby library to do the task for me. I  
> >> wrote a matrix class which knows how to do matrix math on strings,  
> >> producing formulae from them. After the initial pass produced a  
> >> lot of values like "0*sinX" and "0 + 0 + 1*(sinX)" I made it a bit  
> >> smarter, so that 0s and 1s properly simplify the equations during  
> >> calculation.
> >>
> >> It doesn't produce perfectly-reduced equations by any means, but  
> >> it did the trick. In the end, I got my result :)
> > on a related note
> >
> >   http://blade.nagaokaut.ac.jp/~sinara/ruby/math
> >   http://blade.nagaokaut.ac.jp/~sinara/ruby/math/algebra/
> 
> Do you (or anyone else) use this library? I _barely_ understand how  
> to set up a single polynomial function using it (what is a 'ring'  
> anyhow?),

http://en.wikipedia.org/wiki/Ring_%28mathematics%29

As an example, the set of integers Z (positive and negative) is a Ring.
(but not the positive integers only). You have a the common addition and
multiplication, but not division. The set of polynomials on a field is
also a Ring.

That said, I can't help you with the math library as I've never used
it :(.

Guillaume.