source: trunk/c++_tools/random/random.cc @ 675

Last change on this file since 675 was 675, checked in by Jari Häkkinen, 15 years ago

References #83. Changing project name to yat. Compilation will fail in this revision.

  • Property svn:eol-style set to native
  • Property svn:keywords set to Id
File size: 2.2 KB
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1// $Id: random.cc 675 2006-10-10 12:08:45Z jari $
2
3/*
4  Copyright (C) 2005, 2006 Jari Häkkinen, Peter Johansson
5
6  This file is part of the yat library, http://lev.thep.lu.se/trac/yat
7
8  The yat library is free software; you can redistribute it and/or
9  modify it under the terms of the GNU General Public License as
10  published by the Free Software Foundation; either version 2 of the
11  License, or (at your option) any later version.
12
13  The yat library is distributed in the hope that it will be useful,
14  but WITHOUT ANY WARRANTY; without even the implied warranty of
15  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16  General Public License for more details.
17
18  You should have received a copy of the GNU General Public License
19  along with this program; if not, write to the Free Software
20  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
21  02111-1307, USA.
22*/
23
24#include "yat/random/random.h"
25#include "yat/statistics/Histogram.h"
26
27#include <fstream>
28#include <iostream>
29
30
31namespace theplu {
32namespace random {
33
34
35  RNG* RNG::instance_ = NULL;
36
37
38  RNG::RNG(void)
39  {
40    gsl_rng_env_setup();  // support rng/seed changes through environment vars
41    rng_ = gsl_rng_alloc(gsl_rng_default);  // Memory is allocated here!
42  }
43
44
45
46  RNG::~RNG(void)
47  {
48    gsl_rng_free(rng_);
49    rng_=NULL;
50    delete instance_;
51  }
52
53
54 
55  u_long RNG::seed_from_devurandom(void)
56  {
57    u_char ulongsize=sizeof(u_long);
58    char* buffer=new char[ulongsize];
59    std::ifstream is("/dev/urandom");
60    is.read(buffer,ulongsize);
61    is.close();
62    u_long s=0;
63    for (u_int i=0; i<ulongsize; i++) {
64      u_char ch=buffer[i];
65      s+=ch<<((ulongsize-1-i)*8);
66    }
67    seed(s);
68    return s;
69  }
70
71
72
73  int RNG::set_state(const RNG_state& state)
74  {
75    return gsl_rng_memcpy(rng_, state.rng());
76  }
77
78
79
80  RNG_state::RNG_state(const RNG* rng)
81  {
82    rng_ = gsl_rng_clone(rng->rng()); 
83  }
84 
85
86
87  RNG_state::~RNG_state(void)
88  {
89    gsl_rng_free(rng_);
90    rng_=NULL;
91  }
92
93
94
95  DiscreteGeneral::DiscreteGeneral(const statistics::Histogram& hist)
96  {
97    double* p = new double[ hist.nof_bins() ];
98    for (size_t i=0; i<hist.nof_bins(); i++) 
99      p[ i ] = hist[i];
100    gen_ = gsl_ran_discrete_preproc( hist.nof_bins(), p );
101    delete p;
102  }
103
104
105
106  DiscreteGeneral::~DiscreteGeneral(void)
107  {
108    if (gen_)
109      gsl_ran_discrete_free( gen_ );
110    gen_ = NULL;
111  }
112
113
114}} // of namespace random and namespace theplu
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