00001 // simple random number generator class taken from nlojet++. 00002 // $Id: BasicRandom.cc 621 2007-05-09 10:34:30Z salam $ 00003 00004 // Copyright (C) 2002 Zoltan Nagy 00005 // 00006 // This program is free software; you can redistribute it and/or modify 00007 // it under the terms of the GNU General Public License as published by 00008 // the Free Software Foundation; either version 2 of the License, or 00009 // (at your option) any later version. 00010 // 00011 // This program is distributed in the hope that it will be useful, 00012 // but WITHOUT ANY WARRANTY; without even the implied warranty of 00013 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 00014 // GNU General Public License for more details. 00015 // 00016 // You should have received a copy of the GNU General Public License 00017 // along with this program; if not, write to the Free Software 00018 // Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 00019 00020 // nlo includes 00021 #include "fastjet/internal/BasicRandom.hh" 00022 00023 00024 FASTJET_BEGIN_NAMESPACE // defined in fastjet/internal/base.hh 00025 00026 00027 // 00028 // random number generator 00029 // uses method of L'Ecuyer, (via F.James, comp. phys. comm. 60(1990)329) 00030 // 00031 int __default_random_generator(int *__iseed) 00032 { 00033 int __k = __iseed[0]/53668; 00034 __iseed[0] = (__iseed[0] - __k*53668)*40014 - __k*12211; 00035 if(__iseed[0] < 0) __iseed[0] += 2147483563; 00036 00037 __k = __iseed[1]/52774; 00038 __iseed[1] = (__iseed[1] - __k*52774)*40692 - __k*3791; 00039 if(__iseed[1] < 0) __iseed[1] += 2147483399; 00040 00041 int __iz = __iseed[0] - __iseed[1]; 00042 if(__iz < 1) __iz += 2147483562; 00043 00044 return __iz; 00045 } 00046 00047 // global defined random number generator 00048 BasicRandom<int> _G_random_int; 00049 BasicRandom<double> _G_random_double; 00050 00051 00052 FASTJET_END_NAMESPACE 00053