Re: Symbolic Differentiation

[Geoff Leyland <geoff_leyland@...>]

On 8/05/2009, at 2:56 AM, steve donovan wrote:

> Hi all,
>
> http://lua-users.org/wiki/SymbolicDifferentiation

Hi Steve,

Thanks for that.

Rima, my as-yet-unreleased-why-did-I-decide-to-rewrite-when-it-was- 
nearly-working binding to MP solvers handles symbolic expressions to a  
limited extent.  Rather than differentiation, the goal is to simplify  
expressions into linear equations - as you'd expect for LP - but  
there's some similarity.

I think I'll delay things further and make a few changes to pinch some  
of your good ideas and so that it matches a little better what you've  
done, and I'd be keen to swap notes once I've got something out there  
to look at.

I've had a quick look at your code, but I can't work this one out:   
what's the result of differentiating 3*x^2 + 5*x^2?  That is, does it  
gather terms that aren't exactly alike?

Cheers,
Geoff