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Re: GSL_Wigner_6J error
- From: Peter Roche <P dot J dot P dot Roche at damtp dot cam dot ac dot uk>
- To: Gerard Jungman <jungman at lanl dot gov>
- Cc: iwamae at kues dot kyoto-u dot ac dot jp, <gsl-discuss at sources dot redhat dot com>
- Date: Wed, 20 Nov 2002 20:30:18 +0000 (GMT)
- Subject: Re: GSL_Wigner_6J error
I think the convention is like that which relates the Racah W
coefficients and Wigner 6J symbols:
W(Ja Jb Jc Jd; Je Jf) = pow(-1,(Ja+Jb+Jc+Jd)) / Ja Jb Je \
\ Jd Jc Jf /
I think the simplest way to solve the problem is change the manual entry,
rather than the source code?
Regards,
Peter
*********************************************************
Peter Roche
Department of Applied Mathematics and Theoretical Physics,
University of Cambridge, Silver Street, Cambridge, CB3 9EW
email: p.j.p.roche@damtp.cam.ac.uk
*********************************************************
On 20 Nov 2002, Gerard Jungman wrote:
>
> Hi all. Sorry for the confusion here. I implemented this code,
> but I never looked closely at it. Is there a consensus about
> how it should work? It is definitely true that, as implemented,
> the function returns
>
> / Ja Jb Je \
> \ Jd Jc Jf /
>
> I'm not sure where this convention comes from, if anywhere.
>
> Should I change the interface or just change the documentation?
>
> Thanks.
>
> --
> G. Jungman
>
>
> On Mon, 2002-11-18 at 11:07, Peter Roche wrote:
> > Cheers, that solved the problem.
> >
> > Peter
> >
> > *********************************************************
> >
> > Peter Roche
> > Department of Applied Mathematics and Theoretical Physics,
> > University of Cambridge, Silver Street, Cambridge, CB3 9EW
> >
> > email: p.j.p.roche@damtp.cam.ac.uk
> >
> > *********************************************************
> >
> > On Thu, 14 Nov 2002, iwamae atsushi wrote:
> >
> > > Dear Peter
> > >
> > > One of my friend have found the same problem on the 6j symbol in GSL.
> > > In order to get the correct value, the order of J value should be written
> > > as
> > > follows,
> > >
> > > gsl_sf_coupling_6j(Ja, Jb, Jc, Jd, Je, Jf)
> > >
> > > { Ja, Jb, Je }
> > > Jd, Jc, Jf
> > >
> > > The manual discription is not consistent.
> > > It says
> > > {Ja, Jb, Jc}
> > > Jd, Je, Jf
> > > , but this order gives wrong value as you noticed
> > >
> > >
> > >
> > >
> > > Atsushi Iwamae
> > >
> > >
> > > >From: Peter Roche <P.J.P.Roche@damtp.cam.ac.uk>
> > > >To: gsl-discuss@sources.redhat.com
> > > >Subject: GSL_Wigner_6J error
> > > >Date: Wed, 13 Nov 2002 19:36:40 +0000 (GMT)
> > > >
> > > >
> > > >Dear All,
> > > >
> > > >I hope this isn't a repeat of an already dealt with problem. I have been
> > > >trying to use the GSL Wigner 6j coefficients routines
> > > >(gsl_sf_coupling_6j(2*ja, 2*jb, 2*jc, 2*jd,2*je,2*jf)) and have found,
> > > >I think, that some of the returned values from the GSL
> > > >routine are not correct, even for small input values.
> > > >
> > > >I have included a table showing, in the first column, the input
> > > >parameter values, the angular mometa (which are multiplied by 2 in my
> > > >actual program), the second column shows the 'correct' values, obtained
> > > >from another program/published tables, and the third column shows the
> > > >return values from the GSL routine.
> > > >
> > > > Input Correct values GSL return
> > > > (011100) 0.5773502691896257 0.0000000000000000
> > > > (101101) 0.3333333333333335 0.0000000000000000
> > > > (121101) 0.3333333333333334 0.0000000000000000
> > > > (101101) 0.3333333333333335 0.0000000000000000
> > > > (022200) 0.4472135954999579 0.0000000000000000
> > > > (132201) 0.2581988897471612 0.0000000000000000
> > > > (242202) 0.2000000000000000 0.0000000000000000
> > > > (213302) 0.1690308509457034 0.0000000000000000
> > > > (233302) 0.1690308509457033 0.0000000000000000
> > > > (253302) 0.1690308509457033 0.0000000000000000
> > > >
> > > >
> > > >Has anyone encountered the same problems, or can explain the differences.
> > > >
> > > >Cheers,
> > > >Peter Roche
> > > >
> > > >*********************************************************
> > > >
> > > >Peter Roche
> > > >Department of Applied Mathematics and Theoretical Physics,
> > > >University of Cambridge, Silver Street, Cambridge, CB3 9EW
> > > >
> > > >email: p.j.p.roche@damtp.cam.ac.uk
> > > >
> > > >*********************************************************
> > >
> > >
> > > _________________________________________________________________
> > > $B%&%$%k%9%a!<%k!"LBOG%a!<%kBP:v$J$i(B MSN Hotmail http://www.hotmail.com/
> > >
> > >
> --
> Gerard Jungman <jungman@lanl.gov>
> Los Alamos National Laboratory
>
>