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Calculator Community => TI Calculators => General Calculator Help => Topic started by: vanchagreen on August 15, 2010, 08:46:07 pm

Title: Rref Algorithm
Post by: vanchagreen on August 15, 2010, 08:46:07 pm
I'm not sure if this is the right category, but here it goes...

I was wondering if anyone knew what algorithm the calculator uses in its ref() and rref() matrix functions?
Title: Re: Rref Algorithm
Post by: Quigibo on August 15, 2010, 09:02:06 pm
I'm guessing they use Gaussian Elimination (http://en.wikipedia.org/wiki/Gaussian_elimination)
Title: Re: Rref Algorithm
Post by: nemo on August 15, 2010, 09:11:06 pm
RREF stands for Row Reduced Echelon Form, and Here (http://www.youtube.com/watch?v=9LYVi-n-6Jw&feature=fvw) is a good tutorial on how to do it, and gives a good use for it.

edit: and if you're very familiar with matrix operations and terminology, here's a more advanced article (http://unapologetic.wordpress.com/2009/09/03/reduced-row-echelon-form).
Title: Re: Rref Algorithm
Post by: vanchagreen on August 15, 2010, 09:33:16 pm
@Quigibo: I'll look into it. Even if the calc doesn't use it, it looks interesting.

@nemo: When I was learning how to do it over the summer for a summer packet (school started last week...), I came across that same youtube tutorial. It _is_ good. The other one's a little over my head though. :)
Title: Re: Rref Algorithm
Post by: ACagliano on January 15, 2012, 08:47:20 pm
How would you do an rref in z80?
Title: Re: Rref Algorithm
Post by: AngelFish on January 15, 2012, 08:56:46 pm
You would use either floating point numbers (recommended) and regular gaussian elimination algorithms or you could use the division-free variants if you had arbitrary precision integer operations available. I'd recommend obtaining a copy of "Algorithms for Computer Algebra" by Geddes et al. if you want an in depth explanation.