Re: 3j, 6j 9j symbol (was Special functions, Quaternions, Octonions)

From: Hubert HOLIN (Hubert.Holin_at_[hidden])
Date: 2001-04-16 09:20:36

Paris (U.E.), le 16/04/2001

        Hi

                If you wish, once the submission process for quaternions & 
all is over (one way or another), I'll have a look (I'll have to go to 
the University's math library to take a look at A&S, but any additional 
pointer is welcome).

                By the way, what context are these things usefull in?

                        Hubert Holin
                        Hubert.Holin_at_[hidden]

--- In boost_at_y..., Peter Schmitteckert (boost) <boost_at_s...> wrote:
> Salut,
> 
> On Thursday 12 April 2001 13:31, you wrote:
> [...]
> > > BTW: Looking at this package I wondered if someone is working
> > >      on Clebsch-Gordon coefficients and 3j, 6j and 9j symbols?
> >
> > If these are easily computed, I may be able to use NTL very high accuracy
> > to calculate then for 128-bit floating point use like math constants.
> >
> > Paul
> 
> It's just a terrible mess of +,-,*,/ and a few sqrts.
> Most of the calculation can be done using integers,
> but currently I only needed special 3j symbols for
> which explicit formulas are known.
> Please note that 3j symbols are not just number but real valued functions
> taking 6 integer parameters,
> e.g. ClebschGordon_3j( j1, m1, j2, m2, j3, m3) ; j_i>=0; abs(m_i) <= j_i
> corresponding to the coupling of two angular moments to a third one.
> 
> Best wishes,
> Peter