1 /**************************************************************************
2 * Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. *
4 * Author: The ALICE Off-line Project. *
5 * Contributors are mentioned in the code where appropriate. *
7 * Permission to use, copy, modify and distribute this software and its *
8 * documentation strictly for non-commercial purposes is hereby granted *
9 * without fee, provided that the above copyright notice appears in all *
10 * copies and that both the copyright notice and this permission notice *
11 * appear in the supporting documentation. The authors make no claims *
12 * about the suitability of this software for any purpose. It is *
13 * provided "as is" without express or implied warranty. *
14 **************************************************************************/
18 //-----------------------------------------------------------------------------
19 // Class: AliPythiaRndm
20 // Responsibilities: Interface to Root random number generator
21 // from Fortran (re-implements FINCTION PYR from PYTHIA)
22 // Very similar to AliHijingRndm
23 // Collaborators: AliPythia and AliGenPythia classes
26 // root> AliPythia::Instance();
27 // root> AliPythiaRndm::SetPythiaRandom(new TRandom3());
28 // root> AliPythiaRndm::GetPythiaRandom()->SetSeed(0);
29 // root> cout<<"Seed "<< AliPythiaRndm::GetPythiaRandom()->GetSeed() <<endl;
31 //-----------------------------------------------------------------------------
36 #include "AliPythiaRndm.h"
38 TRandom * AliPythiaRndm::fgPythiaRandom=0;
40 ClassImp(AliPythiaRndm)
43 //_______________________________________________________________________
44 void AliPythiaRndm::SetPythiaRandom(TRandom *ran) {
46 // Sets the pointer to an existing random numbers generator
48 if(ran) fgPythiaRandom=ran;
49 else fgPythiaRandom=gRandom;
52 //_______________________________________________________________________
53 TRandom * AliPythiaRndm::GetPythiaRandom() {
55 // Retrieves the pointer to the random numbers generator
57 if (!fgPythiaRandom) fgPythiaRandom=gRandom;
58 return fgPythiaRandom;
61 //_______________________________________________________________________
63 #define pygauss pygauss_
64 #define pyrset pyrset_
65 #define pyrget pyrget_
70 // Wrapper to FUNCTION PYR from PYTHIA
71 // Uses static method to retrieve the pointer to the (C++) generator
73 do r=AliPythiaRndm::GetPythiaRandom()->Rndm();
74 while(0 >= r || r >= 1);
78 Double_t pygauss(Double_t x0, Double_t sig)
85 v1 = 2. * pyr(0) - 1.;
86 v2 = 2. * pyr(0) - 1.;
87 s = v1 * v1 + v2 * v2;
89 return v1 * TMath::Sqrt(-2. * TMath::Log(s) / s) * sig + x0;
92 void pyrset(Int_t*,Int_t*) {}
93 void pyrget(Int_t*,Int_t*) {}