Re: Review Request: Special functions, Quaternions, Octonions

From: Hubert HOLIN (Hubert.Holin_at_[hidden])
Date: 2001-04-11 16:50:06

Paris (U.E.), le 11/04/2001

--- In boost_at_y..., Peter Schmitteckert (boost) <boost_at_s...> wrote:
> Salut,
> 
> On Tuesday 10 April 2001 22:58, you wrote:
> [...]
> > 		I would like to request a review of the following three
> > libraries:
> >
> > 	1) Special functions
> >
> [...]
> 
> I just had a short look at the "Special functions",
> and I would like to suggest to rename the packet.
> This packet define a few extensions to the trigonometric
> functions, which I wouldn't call special functions.
> 
> AFAIK the notion of s"special functions" refers to:
> ->Gamma-, Beta-, incomplete Gamma-, Error-,
>     Chi-square-  functions, probability functions,
> -> exponential integrals, all kind of Bessel functions,
> -> hypergeometric functions, 
> -> elliptic integrals, Cosine & SIne & Dawson integral
> -> sperical harmonics
> 
>  & ... more stuff you can find in "Abramowitz  & Stegun"
> 
> Best wishes,
> Peter

                Actually, a "special function" is any function one cares to 
name... Those in A&S are merely some of the most well-known 
(essentially because they are the most usefull).

                That being said, calling the file as I did 
"special_functions.hpp" is indeed pompously overblown...

                I would like the name to stay, however, if only as a place 
holder. It is my hope that it will serve as the nucleus of a bona fide 
special functions library (note that my implementations there are 
simply stop-gap entries of some of the functions I happened to need at 
some time or another, including for the quaternions, in addition to 
being ridiculously few). Ideally, this will encompass the successor to 
A&S (http://dlmf.nist.gov/). That will necessarilly entail the 
decomposition into several files, of which this one will be but one 
among many. One has to take a first step, anyway. This is just one of 
the first steps, also, of a possible numerical section of boost, along 
with the "Math Constants Library" soon under review (by another 
contributor), and "More Math", and of course with the matrices, or 
(multi-)linear algebra, libraries taking shape. One could then also 
dream about a boostification of COOOL (http://timna.Mines.EDU/cwpcodes/
coool/).

                In the end, of course, I have no objection to changing the 
name, and I am open to any suggestion.

        Best Regards

                        Hubert Holin
                        Hubert.Holin_at_[hidden]

> 
> BTW: Looking at this package I wondered if someone is working
> 	on Clebsch-Gordon coefficients and 3j, 6j and 9j symbols?

P.S.: Well, wouldn't that be a nice thing to do? ;-)