* gsl_sf_coupling_3j
@ 2002-10-02 8:46 Filip Floegel
2002-10-03 13:21 ` gsl_sf_coupling_3j Brian Gough
0 siblings, 1 reply; 7+ messages in thread
From: Filip Floegel @ 2002-10-02 8:46 UTC (permalink / raw)
To: gsl-discuss
hello gsl community,
gsl_sf_coupling_3j doesn't work properly for large
angular mementa like j1=j2=j3=40 m1=m2=m3=0 !!!
gsl_sf_coupling_3j_e(80,80,80,0,0,0,&result)
which correspond to j1=j2=j3=40 m1=m2=m3=0
gives me:
result.val = 0.0625
result.err = 0.172766
mathematica gives me:
N[ThreeJSymbol[{40,0},{40,0},{40,0}]] = 0.0149685
my guess is that gamma.c which is used for calculating fractional
numbers probably diverges for large integers.
cheers,
ff
--
+---------------------------------------------------------------+
| dipl.phys. Filip Floegel e-mail:floegel@itp.uni-hannover.de |
| ITP/Universitaet Hannover phone: 0511/762-3381 |
| Appelstr.2 fax: 0511/762-4945 |
| 30167 Hannover |
| |
+---------------------------------------------------------------+
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: gsl_sf_coupling_3j
2002-10-02 8:46 gsl_sf_coupling_3j Filip Floegel
@ 2002-10-03 13:21 ` Brian Gough
0 siblings, 0 replies; 7+ messages in thread
From: Brian Gough @ 2002-10-03 13:21 UTC (permalink / raw)
To: Filip Floegel; +Cc: gsl-discuss
Filip Floegel writes:
> hello gsl community,
> gsl_sf_coupling_3j doesn't work properly for large angular mementa
> like j1=j2=j3=40 m1=m2=m3=0 !!!
> gsl_sf_coupling_3j_e(80,80,80,0,0,0,&result)
> which correspond to j1=j2=j3=40 m1=m2=m3=0
> gives me:
> result.val = 0.0625 result.err = 0.172766
> mathematica gives me:
> N[ThreeJSymbol[{40,0},{40,0},{40,0}]] = 0.0149685
> my guess is that gamma.c which is used for calculating fractional
> numbers probably diverges for large integers.
Thanks for the bug report.
If you can take a look at the source maybe a different expansion can
be used for large values to improve the accuracy?
Brian
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: Abramowitz and Stegun (1964) online
@ 2002-10-09 12:04 Brian Gough
2002-10-15 6:55 ` gsl_sf_coupling_3j Serge Winitzki
0 siblings, 1 reply; 7+ messages in thread
From: Brian Gough @ 2002-10-09 12:04 UTC (permalink / raw)
To: Serge Winitzki; +Cc: gsl-discuss
Serge Winitzki writes:
> Hi,
> Thanks for a great library! I use it in my research.
Thanks. If you'd like to cite GSL in any papers a suitable reference
is:
GNU Scientific Library Reference Manual, M. Galassi et al,
ISBN 095416170X
> In the TODO file, I noticed a wish to distribute Abramowitz and
> Stegun with GSL. It seems that the old edition Abramowitz and
> Stegun is now available online
> (http://members.fortunecity.com/aadns/) as page images, total about
> 50 MB. (Just to let you know.)
Wow that's good news. I didn't know about it, thanks for posting the
information.
(corrected url for the list: http://members.fortunecity.com/aands/)
Do you have any idea how to contact the person behind it? I could not
find any information on the site itself.
Brian
^ permalink raw reply [flat|nested] 7+ messages in thread
* gsl_sf_coupling_3j
@ 2002-12-31 9:55 jdwright
2002-05-21 7:39 ` gsl_sf_coupling_3j jdwright
2002-12-31 9:55 ` gsl_sf_coupling_3j Brian Gough
0 siblings, 2 replies; 7+ messages in thread
From: jdwright @ 2002-12-31 9:55 UTC (permalink / raw)
To: gsl-discuss
Dear gsl users,
Does anyone out there have experience using the "gsl_sf_coupling_3j" routine of
the "gsl_sf_coupling" package? I wonder if the call:
gsl_sf_coupling_3j (two_ja,two_jb,two_jc,two_ma,two_mb,two_mc)
yields accurate results for large values of two_ja, two_jb, and two_jc around 30
with two_ma=0,two_mb=0,two_mc=0.
Thanks,
J. David Wright
Physics Department
Wesleyan University
jdwright@wesleyan.edu
^ permalink raw reply [flat|nested] 7+ messages in thread
* gsl_sf_coupling_3j
2002-12-31 9:55 gsl_sf_coupling_3j jdwright
@ 2002-05-21 7:39 ` jdwright
2002-12-31 9:55 ` gsl_sf_coupling_3j Brian Gough
1 sibling, 0 replies; 7+ messages in thread
From: jdwright @ 2002-05-21 7:39 UTC (permalink / raw)
To: gsl-discuss
Dear gsl users,
Does anyone out there have experience using the "gsl_sf_coupling_3j" routine of
the "gsl_sf_coupling" package? I wonder if the call:
gsl_sf_coupling_3j (two_ja,two_jb,two_jc,two_ma,two_mb,two_mc)
yields accurate results for large values of two_ja, two_jb, and two_jc around 30
with two_ma=0,two_mb=0,two_mc=0.
Thanks,
J. David Wright
Physics Department
Wesleyan University
jdwright@wesleyan.edu
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: gsl_sf_coupling_3j
2002-12-31 9:55 gsl_sf_coupling_3j jdwright
2002-05-21 7:39 ` gsl_sf_coupling_3j jdwright
@ 2002-12-31 9:55 ` Brian Gough
2002-05-21 14:14 ` gsl_sf_coupling_3j Brian Gough
1 sibling, 1 reply; 7+ messages in thread
From: Brian Gough @ 2002-12-31 9:55 UTC (permalink / raw)
To: jdwright; +Cc: gsl-discuss
jdwright@wesleyan.edu writes:
> Dear gsl users,
> Does anyone out there have experience using the
> "gsl_sf_coupling_3j" routine of the "gsl_sf_coupling" package? I
> wonder if the call:
> gsl_sf_coupling_3j (two_ja,two_jb,two_jc,two_ma,two_mb,two_mc)
> yields accurate results for large values of two_ja, two_jb, and
> two_jc around 30 with two_ma=0,two_mb=0,two_mc=0.
> Thanks,
> J. David Wright Physics Department Wesleyan University
> jdwright@wesleyan.edu
The result->error term from the full version of the function
gsl_sf_coupling_3j_e() should give an estimate of the error.
If it's not accurate please send a bug report, thanks. The exact
value could be computed to high precision using GP-PARI, which is free
software.
regards
Brian Gough
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: gsl_sf_coupling_3j
2002-12-31 9:55 ` gsl_sf_coupling_3j Brian Gough
@ 2002-05-21 14:14 ` Brian Gough
0 siblings, 0 replies; 7+ messages in thread
From: Brian Gough @ 2002-05-21 14:14 UTC (permalink / raw)
To: jdwright; +Cc: gsl-discuss
jdwright@wesleyan.edu writes:
> Dear gsl users,
> Does anyone out there have experience using the
> "gsl_sf_coupling_3j" routine of the "gsl_sf_coupling" package? I
> wonder if the call:
> gsl_sf_coupling_3j (two_ja,two_jb,two_jc,two_ma,two_mb,two_mc)
> yields accurate results for large values of two_ja, two_jb, and
> two_jc around 30 with two_ma=0,two_mb=0,two_mc=0.
> Thanks,
> J. David Wright Physics Department Wesleyan University
> jdwright@wesleyan.edu
The result->error term from the full version of the function
gsl_sf_coupling_3j_e() should give an estimate of the error.
If it's not accurate please send a bug report, thanks. The exact
value could be computed to high precision using GP-PARI, which is free
software.
regards
Brian Gough
^ permalink raw reply [flat|nested] 7+ messages in thread
end of thread, other threads:[~2002-10-15 13:55 UTC | newest]
Thread overview: 7+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2002-10-02 8:46 gsl_sf_coupling_3j Filip Floegel
2002-10-03 13:21 ` gsl_sf_coupling_3j Brian Gough
2002-10-09 12:04 Abramowitz and Stegun (1964) online Brian Gough
2002-10-15 6:55 ` gsl_sf_coupling_3j Serge Winitzki
2002-12-31 9:55 gsl_sf_coupling_3j jdwright
2002-05-21 7:39 ` gsl_sf_coupling_3j jdwright
2002-12-31 9:55 ` gsl_sf_coupling_3j Brian Gough
2002-05-21 14:14 ` gsl_sf_coupling_3j Brian Gough
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