On Wed, 8 Jun 2005, Gavin Kistner wrote:

> (This isn't a library I plan on maintaining, but ANN felt like the right 
> prefix for offering up code for mass enjoyment.)
>
> At work yesterday I needed to do some algebra on some matrix math to 
> reverse-derive a value. (To be specific, I needed to figure out how to draw 
> the three euler rotation values out of a ZXY rotation matrix.) After spending 
> 2 minutes writing out equations and fearing I was making a mistake, I turned 
> to Excel and some stupid text manipulation to produce my formulae. After 10 
> minutes of messing around, I got the answer wrong anyhow.
>
> 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/

cheers.

-a
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