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>-Original Message-
>From: Gabor Grothendieck [mailto:ggrothendi...@gmail.com]
>Sent: Tuesday, May 19, 2009 2:58 PM
>To: Martin Maechler
>Cc: John C Nash; r-devel@r-project.org; Forth, Shaun
>Subject: Re:
On Tue, May 19, 2009 at 9:08 AM, Martin Maechler
wrote:
> [MM stumbling over on old thread ... he'd be interested]
>
>> "GaGr" == Gabor Grothendieck
>> on Wed, 15 Apr 2009 09:53:18 -0400 writes:
>
> GaGr> Not sure if this is sufficient for your needs but R does include
> symbolic
Martin (see below) gives a good explanation of the difference between AD and
symbolic
differentiations. I'm of the opinion we can use both. However, the real issue
as far
as I'm concerned (from an optimizer's point of view, which may also be that of
ODE and
PDE folk) is that right now none of t
[MM stumbling over on old thread ... he'd be interested]
> "GaGr" == Gabor Grothendieck
> on Wed, 15 Apr 2009 09:53:18 -0400 writes:
GaGr> Not sure if this is sufficient for your needs but R does include
symbolic
GaGr> differentiation, see ?D, and the Ryacas and rSymPy
G
Not sure if this is sufficient for your needs but R does include symbolic
differentiation, see ?D, and the Ryacas and rSymPy
packages interface R to the yacas and sympy computer algebra
systems (CAS) and those system include symbolic differentiation.
http://ryacas.googlecode.com
http://rsympy.goog
In efforts to improve optimization tools for R, one of my
interests has been getting automatic differentiation capabilities
so that analytic rather than numerical derivatives can be used. They
would be helpful in several other areas besides optimization, My timings
show
factors of the order of 1
