[Fwd: Re: libevaluator library and GSL]

[Jerome BENOIT <jgmbenoit at wanadoo dot fr>]

-------- Original Message --------
Subject: Re: libevaluator library and GSL
Date: Thu, 04 Sep 2003 21:33:48 +0300
From: Jerome BENOIT <jgmbenoit@wanadoo.fr>
Reply-To: jgmbenoit@wanadoo.fr
Organization: UOC
To: Martin Jansche <jansche@ling.ohio-state.edu>
References: 
<Pine.SOL.4.33.0309041408390.26887-100000@julius.ling.ohio-state.edu>



Martin Jansche wrote:
> On Thu, 4 Sep 2003, Aleksandar B. Samardzic wrote:
>
>
>>I've written a library
>>(http://savannah.nongnu.org/projects/libevaluator/) that makes
>>possible to parse strings representing mathematical functions over
>>single or multiple variables and later to evaluate these functions
>>for different variable values (also to create representation of
>>function derivative over specified variable etc.).
>
>
> I'm only speaking for myself here: I'd like to have some of this
> functionality available, but in a different form.  Specifically, I'd
> prefer a formula-to-code translator which, given a symbolic formula,
> would generate C code with calls to GSL functions (and could possibly
> have other backends in addition).  That way, I can manually change the
> generated code if necessary, plus it would presumably speed things up
> if one were to use optimized compiled code instead of formulas that
> need to be interpreted online.

Maple provides the package `Codegen' to that


>
> Could you tell us more about what your evaluator does?  How does it
> compute derivatives?  Symbolically or numerically?  Does it simplify
> formulas?  Does it look for common subexpressions?  A number of the
> optimizations one might want to do could be done by a compiler
> (another reason to generate C source code).
>
> For me, what it boils down to is this: if I want to quickly optimize
> or integrate a symbolic function, I use Mathematica or some other
> symbolic algebra system.  I use GSL for fixed, narrow tasks that have
> to be run many times; in that case I need the code to be as efficient
> as possible.  Now if there were a forumla translator that could read
> Mathematica formulas (it uses a nice XML encoding) or Octave formulas
> etc. and spit out GSL C code, that would be very useful.
>
> - martin
>
>



--
Jerome BENOIT, Ph.D.
JGMBenoit@wanadoo.fr