FastJet  3.0.6
BasicRandom.cc
1 //STARTHEADER
2 // simple random number generator class taken from nlojet++.
3 // $Id: BasicRandom.cc 2471 2011-07-26 09:54:37Z cacciari $
4 //
5 // Copyright (C) 2002 Zoltan Nagy
6 //
7 // This program is free software; you can redistribute it and/or modify
8 // it under the terms of the GNU General Public License as published by
9 // the Free Software Foundation; either version 2 of the License, or
10 // (at your option) any later version.
11 //
12 // This program is distributed in the hope that it will be useful,
13 // but WITHOUT ANY WARRANTY; without even the implied warranty of
14 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 // GNU General Public License for more details.
16 //
17 // You should have received a copy of the GNU General Public License
18 // along with this program; if not, write to the Free Software
19 // Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
20 //ENDHEADER
21 
22 // nlo includes
23 #include "fastjet/internal/BasicRandom.hh"
24 
25 
26 FASTJET_BEGIN_NAMESPACE // defined in fastjet/internal/base.hh
27 
28 
29 //
30 // random number generator
31 // uses method of L'Ecuyer, (via F.James, comp. phys. comm. 60(1990)329)
32 //
33 int __default_random_generator(int *__iseed)
34 {
35  int __k = __iseed[0]/53668;
36  __iseed[0] = (__iseed[0] - __k*53668)*40014 - __k*12211;
37  if(__iseed[0] < 0) __iseed[0] += 2147483563;
38 
39  __k = __iseed[1]/52774;
40  __iseed[1] = (__iseed[1] - __k*52774)*40692 - __k*3791;
41  if(__iseed[1] < 0) __iseed[1] += 2147483399;
42 
43  int __iz = __iseed[0] - __iseed[1];
44  if(__iz < 1) __iz += 2147483562;
45 
46  return __iz;
47 }
48 
49 // global defined random number generator
50 BasicRandom<int> _G_random_int;
51 BasicRandom<double> _G_random_double;
52 
53 
54 FASTJET_END_NAMESPACE
55