GSI Helmholtzzentrum für Schwerionenforschung
Hi, I added time stamps to the MCEventHeader (r 2772), to use this in the simulation macro: CbmPrimaryGenerator* primGen = new CbmPrimaryGenerator(); primGen->SetEventTimeInterval ( minTime, maxTime) ; the event time will be a random number between minTime and maxTime in nano secounds, it will also be added for each event, i.e: each event will have the time of all previous events+ its own one! regards Mohammad
Very good! What is the random generator you use? I think it should be a random distribution. Cheers, Tobias
Hi, I use: TRandom::Uniform(min, max) is this enough or should we change it! or should the user have the possibility to choose the Random generator? Mohammad
Hi Mohammad, it should be an exponential function with the mean time between events (100 ns) as parameter
Hi, Can you explain me in more details what do you mean by this! do you mean the random distribution or the the time it self? Mohammad
Hi Mohammad, the probability distribution of time intervals between two consecutive events is given by: P(t) = 1/meantime * exp (- 1/meantime * t). The meantime should be a free parameter (typically 100 ns). I hope this clarifies it. Have a nice weekend Tobias
Hi, So, I added a new method SetEventMeanTime(Double_t) to the CbmPrimaryGenerator, setting this value will create a TF1 function: TF1 *f1 = TF1("f1", "1/meanTime * Exp (-t/meanTime)", 0, meanTime*10 ) Then the event time is taken randomly from this distribution (f1->GetRandom()) and will be added for each event! Please test it and let me know! regards Mohammad
Hi Mohammad, Or you could use TRandom::Exp(Double_t tau), that does exactly the same faster. Greetings Oscar
Maybe one could just give a TF1 function as parameter, so that the user can set whichever distribution he likes.
Hallo Oscar, You are right, it gives the same results! it is not faster but more simple! so now we have two methods: 1. SetEventMeanTime(Double_t) 2. SetEventTimeInterval ( minTime, maxTime) ; do we need a very general one as Stefano suggested ! regards Mohammad