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joeydumont / wignerSymbols

A C++ library to compute the Wigner 3j- and 6j- symbols (with FORTRAN backend).
GNU Lesser General Public License v3.0
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Wigner 3j returns 0s instead of actual output #2

Closed joeydumont closed 10 years ago

joeydumont commented 10 years ago

Thanks again to @jeffzhen for pointing this out.

In the computation of the Wigner symbol WignerSymbols::wigner3j(529, 992, 1243, 196, -901, 705), the function returns 0 (and the vector function for all allowed l1s returns a string of 0s) while the actual output is close to 1.97986e-18.

This is due to an overflow of the normalization condition. Will need to be fixed.

joeydumont commented 10 years ago

@jeffzhen, could you please retest the new version of the library?

jeffzhen commented 10 years ago

OK, testing now.

On Fri, Jul 18, 2014 at 8:14 PM, Joey Dumont notifications@github.com wrote:

@jeffzhen https://github.com/jeffzhen, could you please retest the new version of the library?

— Reply to this email directly or view it on GitHub https://github.com/valandil/wignerSymbols/issues/2#issuecomment-49493308 .

jeffzhen commented 10 years ago

Hi Joey, Wow, great and fast work! I can confirm that bug #2 was fixed! Your code is probably one of the most capable wigner symbol calculator in the world now ;) Sorry to report bugs non-stop, but here are the last 6 combinations (in my 1000 test cases) that are returning 0: [ 751 856 1200 464 -828 364] -9.41731061215e-58 -0.0 [ 841 379 1011 -631 313 318] -2.44096504011e-41 -0.0 [ 570 1007 1392 327 -933 606] -1.74376347733e-98 0.0 [ 970 727 1202 533 -663 130] -6.93009562166e-12 0.0 [ 905 919 1670 869 -594 -275] -3.48516309858e-195 -0.0 [ 895 574 1392 793 -365 -428] -1.41868655509e-146 -0.0

Thanks a lot! Jeff

On Fri, Jul 18, 2014 at 9:09 PM, Jeff Zheng jeff.h.zheng@gmail.com wrote:

OK, testing now.

On Fri, Jul 18, 2014 at 8:14 PM, Joey Dumont notifications@github.com wrote:

@jeffzhen https://github.com/jeffzhen, could you please retest the new version of the library?

— Reply to this email directly or view it on GitHub https://github.com/valandil/wignerSymbols/issues/2#issuecomment-49493308 .

joeydumont commented 10 years ago

Does your first column after the symbol definition correspond to the "good" outputs?

jeffzhen commented 10 years ago

Hi Joey, Yes, thise are Mathematica outputs.

Thanks a lot! Jeff

Sent from my mobile device On Jul 21, 2014 12:46 PM, "Joey Dumont" notifications@github.com wrote:

Does your first column after the symbol definition correspond to the "good" outputs?

— Reply to this email directly or view it on GitHub https://github.com/valandil/wignerSymbols/issues/2#issuecomment-49631983 .

joeydumont commented 10 years ago

The problem described in this issue has been solved. See #3 for the rest of your test cases.