Message: Re: cannot reproduce rare events with Random Status saved Not Logged In (login)
 Next-in-Thread Next-in-Thread
 Next-in-Forum Next-in-Forum

Feedback Re: cannot reproduce rare events with Random Status saved 

Forum: Event and Track Management
Re: Warning cannot reproduce rare events with Random Status saved (Ilya Kudinov)
Date: 05 Feb, 2013
From: Gumplinger Peter <Gumplinger Peter>

Dear Ilya,

There should be no reason for such behaviour from a bug free Geant4 source. If your events are very rare, then my proposal is not really feasible because it would generate too large of an output. If not, I suggest you turn on

/tracking/verbose 1

and see where the tracking diverges in the two cases; e.g. the event as simulated in sequence versus the event launched from the seed. Is everything the PrimaryGenerator samples still identical and does the tracking diverge later?

Often these things happen because the user inadvertently exercises a second random number generator, or, the primary event generation reads from some file. In that case, although the random generator is correctly set, the place the program points to in the file on the repeat is at the beginning of the file.

If you find the initial event is the same in both cases but later the track history diverges, and you are sure you do not in any of your user actions read from a file or use random numbers that come from another engine, you found a non reproducibility in 9.6. Please, check the bug reports. I think I heard mumbling about one hadronic physics process in 9.6 is not compliant but nothing wrt electromagnetic physics.

In any case, be advised that 9.6 has a serious bug, and other bugs, and awaits a correction patch that will be released soon! What happens if you switch to the most recent patched 9.5?

Peter

Inline Depth:
 1 1
 All All
Outline Depth:
 1 1
 2 2
 All All
Add message: (add)

1 Ok: Re: cannot reproduce rare events with Random Status saved   (Ilya Kudinov - 05 Feb, 2013)
(_ Feedback: Re: cannot reproduce rare events with Random Status saved   (Gumplinger Peter - 06 Feb, 2013)
(_ Feedback: Re: cannot reproduce rare events with Random Status saved   (Gumplinger Peter - 06 Feb, 2013)
 Add Message Add Message
to: "Re: cannot reproduce rare events with Random Status saved"

 Subscribe Subscribe

This site runs SLAC HyperNews version 1.11-slac-98, derived from the original HyperNews


[ Geant 4 Home | Geant 4 HyperNews | Search | Request New Forum | Feedback ]