Hi,

This is actually the case since a couple of version.
If you want to ensure 100% reproducibility you also have to set the python seed in top of the fortran seed that are set within the run_card.

Cheers,

Olivier


> On 4 May 2018, at 23:23, Zachary Marshall <email address hidden> wrote:
> 
> Public bug reported:
> 
> Dear authors,
> 
> I'm running tests with MG5_aMC 2.6.2 - in case you have a CERN account, it's this one:
> /afs/cern.ch/sw/lcg/external/MCGenerators_lcgcmt67c/madgraph5amc/2.6.2.atlas/x86_64-slc6-gcc47-opt/
> 
> We see some non-reproducibility, even when setting a random number seed.
> I attach a tarball of the cards directories so that you have the run,
> param, and proc cards.  For the actual runs, iseed was set to 1234 (of
> course, the code resets it to 0 after the run).
> 
> Looking at the LHE files, they seem to contain the same events, but in
> different order.  Just diffing the two files, you can see an example
> right away:
> 
> 1487a1488,1496
>> 6      1 +8.9242237e-05 3.75379100e+02 7.95049700e-03 1.05265500e-01
>>       21 -1    0    0  501  502 +0.0000000000e+00 +0.0000000000e+00 +2.1196628570e+01 2.1196628570e+01 0.0000000000e+00 0.0000e+00 -1.0000e+00
>>        2 -1    0    0  502    0 -0.0000000000e+00 -0.0000000000e+00 -1.6619322556e+03 1.6619322556e+03 0.0000000000e+00 0.0000e+00 -1.0000e+00
>>       24  2    1    2    0    0 +8.9075749711e+01 +3.5726986208e+01 -1.0898807218e+03 1.1239759236e+03 2.5743150990e+02 0.0000e+00 0.0000e+00
>>  1000023  1    3    3    0    0 +8.0116545705e+01 +1.1392922116e+02 -6.6081705506e+02 6.8029530983e+02 8.2000000000e+01 0.0000e+00 -1.0000e+00
>>  1000024  1    3    3    0    0 +8.9592040060e+00 -7.8202234949e+01 -4.2906366674e+02 4.4368061374e+02 8.1000000000e+01 0.0000e+00 1.0000e+00
>>        1  1    1    2  501    0 -8.9075749711e+01 -3.5726986208e+01 -5.5085490525e+02 5.5915296062e+02 0.0000000000e+00 0.0000e+00 -1.0000e+00
>> </event>
>> <event>
> 1506,1532c1515,1542
> <  6      1 +8.9242237e-05 3.75379100e+02 7.95049700e-03 1.05265500e-01
> <        21 -1    0    0  501  502 +0.0000000000e+00 +0.0000000000e+00 +2.1196628570e+01 2.1196628570e+01 0.0000000000e+00 0.0000e+00 -1.0000e+00
> <         2 -1    0    0  502    0 -0.0000000000e+00 -0.0000000000e+00 -1.6619322556e+03 1.6619322556e+03 0.0000000000e+00 0.0000e+00 -1.0000e+00
> <        24  2    1    2    0    0 +8.9075749711e+01 +3.5726986208e+01 -1.0898807218e+03 1.1239759236e+03 2.5743150990e+02 0.0000e+00 0.0000e+00
> <   1000023  1    3    3    0    0 +8.0116545705e+01 +1.1392922116e+02 -6.6081705506e+02 6.8029530983e+02 8.2000000000e+01 0.0000e+00 -1.0000e+00
> <   1000024  1    3    3    0    0 +8.9592040060e+00 -7.8202234949e+01 -4.2906366674e+02 4.4368061374e+02 8.1000000000e+01 0.0000e+00 1.0000e+00
> <         1  1    1    2  501    0 -8.9075749711e+01 -3.5726986208e+01 -5.5085490525e+02 5.5915296062e+02 0.0000000000e+00 0.0000e+00 -1.0000e+00
> < </event>
> 
> 
> I believe that's the same event, but note that the line numbers are ~20 apart -- this event is first in one file and fourth in the other.  I believe this indicates some non-reproducibility or a race condition in combine somewhere.
> 
> Because these events then enter programs like Pythia8 -- or even when
> they enter MadSpin -- the events are processed in order, the final
> events then appear random (different seeds are applied to the same
> particles).  That means the events are effectively not reproducible when
> processed through, so this is an issue for our bug hunting and for
> various other reasons.
> 
> If you could help us out with this it would be very much appreciated!
> 
> Thanks,
> Zach
> 
> ** Affects: mg5amcnlo
>     Importance: Undecided
>         Status: New
> 
> ** Attachment added: "Cards directory for the jobs in question"
>   https://bugs.launchpad.net/bugs/1769271/+attachment/5134110/+files/Cards_problem.tgz
> 
> -- 
> You received this bug notification because you are subscribed to
> MadGraph5_aMC@NLO.
> https://bugs.launchpad.net/bugs/1769271
> 
> Title:
>  Reproducibility problem in 2.6.2 (in combine?)
> 
> Status in MadGraph5_aMC@NLO:
>  New
> 
> Bug description:
>  Dear authors,
> 
>  I'm running tests with MG5_aMC 2.6.2 - in case you have a CERN account, it's this one:
>  /afs/cern.ch/sw/lcg/external/MCGenerators_lcgcmt67c/madgraph5amc/2.6.2.atlas/x86_64-slc6-gcc47-opt/
> 
>  We see some non-reproducibility, even when setting a random number
>  seed.  I attach a tarball of the cards directories so that you have
>  the run, param, and proc cards.  For the actual runs, iseed was set to
>  1234 (of course, the code resets it to 0 after the run).
> 
>  Looking at the LHE files, they seem to contain the same events, but in
>  different order.  Just diffing the two files, you can see an example
>  right away:
> 
>  1487a1488,1496
>> 6      1 +8.9242237e-05 3.75379100e+02 7.95049700e-03 1.05265500e-01
>>       21 -1    0    0  501  502 +0.0000000000e+00 +0.0000000000e+00 +2.1196628570e+01 2.1196628570e+01 0.0000000000e+00 0.0000e+00 -1.0000e+00
>>        2 -1    0    0  502    0 -0.0000000000e+00 -0.0000000000e+00 -1.6619322556e+03 1.6619322556e+03 0.0000000000e+00 0.0000e+00 -1.0000e+00
>>       24  2    1    2    0    0 +8.9075749711e+01 +3.5726986208e+01 -1.0898807218e+03 1.1239759236e+03 2.5743150990e+02 0.0000e+00 0.0000e+00
>>  1000023  1    3    3    0    0 +8.0116545705e+01 +1.1392922116e+02 -6.6081705506e+02 6.8029530983e+02 8.2000000000e+01 0.0000e+00 -1.0000e+00
>>  1000024  1    3    3    0    0 +8.9592040060e+00 -7.8202234949e+01 -4.2906366674e+02 4.4368061374e+02 8.1000000000e+01 0.0000e+00 1.0000e+00
>>        1  1    1    2  501    0 -8.9075749711e+01 -3.5726986208e+01 -5.5085490525e+02 5.5915296062e+02 0.0000000000e+00 0.0000e+00 -1.0000e+00
>> </event>
>> <event>
>  1506,1532c1515,1542
>  <  6      1 +8.9242237e-05 3.75379100e+02 7.95049700e-03 1.05265500e-01
>  <        21 -1    0    0  501  502 +0.0000000000e+00 +0.0000000000e+00 +2.1196628570e+01 2.1196628570e+01 0.0000000000e+00 0.0000e+00 -1.0000e+00
>  <         2 -1    0    0  502    0 -0.0000000000e+00 -0.0000000000e+00 -1.6619322556e+03 1.6619322556e+03 0.0000000000e+00 0.0000e+00 -1.0000e+00
>  <        24  2    1    2    0    0 +8.9075749711e+01 +3.5726986208e+01 -1.0898807218e+03 1.1239759236e+03 2.5743150990e+02 0.0000e+00 0.0000e+00
>  <   1000023  1    3    3    0    0 +8.0116545705e+01 +1.1392922116e+02 -6.6081705506e+02 6.8029530983e+02 8.2000000000e+01 0.0000e+00 -1.0000e+00
>  <   1000024  1    3    3    0    0 +8.9592040060e+00 -7.8202234949e+01 -4.2906366674e+02 4.4368061374e+02 8.1000000000e+01 0.0000e+00 1.0000e+00
>  <         1  1    1    2  501    0 -8.9075749711e+01 -3.5726986208e+01 -5.5085490525e+02 5.5915296062e+02 0.0000000000e+00 0.0000e+00 -1.0000e+00
>  < </event>
> 
> 
>  I believe that's the same event, but note that the line numbers are ~20 apart -- this event is first in one file and fourth in the other.  I believe this indicates some non-reproducibility or a race condition in combine somewhere.
> 
>  Because these events then enter programs like Pythia8 -- or even when
>  they enter MadSpin -- the events are processed in order, the final
>  events then appear random (different seeds are applied to the same
>  particles).  That means the events are effectively not reproducible
>  when processed through, so this is an issue for our bug hunting and
>  for various other reasons.
> 
>  If you could help us out with this it would be very much appreciated!
> 
>  Thanks,
>  Zach
> 
> To manage notifications about this bug go to:
> https://bugs.launchpad.net/mg5amcnlo/+bug/1769271/+subscriptions