QuantLib: a free/open-source library for quantitative finance
fully annotated source code - version 1.34
Loading...
Searching...
No Matches
seedgenerator.cpp
Go to the documentation of this file.
1/* -*- mode: c++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
2
3/*
4 Copyright (C) 2004 Ferdinando Ametrano
5
6 This file is part of QuantLib, a free-software/open-source library
7 for financial quantitative analysts and developers - http://quantlib.org/
8
9 QuantLib is free software: you can redistribute it and/or modify it
10 under the terms of the QuantLib license. You should have received a
11 copy of the license along with this program; if not, please email
12 <quantlib-dev@lists.sf.net>. The license is also available online at
13 <http://quantlib.org/license.shtml>.
14
15 This program is distributed in the hope that it will be useful, but WITHOUT
16 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
17 FOR A PARTICULAR PURPOSE. See the license for more details.
18*/
19
21#include <ctime>
22#if defined(BOOST_NO_STDC_NAMESPACE)
23 namespace std { using ::time; }
24#endif
25
26namespace QuantLib {
27
28 // we need to prevent rng from being default-initialized
30 initialize();
31 }
32
34
35 // firstSeed is chosen based on clock() and used for the first rng
36 auto firstSeed = (unsigned long)(std::time(nullptr));
37 MersenneTwisterUniformRng first(firstSeed);
38
39 // secondSeed is as random as it could be
40 // feel free to suggest improvements
41 unsigned long secondSeed = first.nextInt32();
42
43 MersenneTwisterUniformRng second(secondSeed);
44
45 // use the second rng to initialize the final one
46 unsigned long skip = second.nextInt32() % 1000;
47 std::vector<unsigned long> init(4);
48 init[0]=second.nextInt32();
49 init[1]=second.nextInt32();
50 init[2]=second.nextInt32();
51 init[3]=second.nextInt32();
52
54
55 for (unsigned long i=0; i<skip ; i++)
57 }
58
59 unsigned long SeedGenerator::get() {
60 return rng_.nextInt32();
61 }
62
63}
Uniform random number generator.
unsigned long nextInt32() const
return a random integer in the [0,0xffffffff]-interval
MersenneTwisterUniformRng rng_
Definition: any.hpp:35
STL namespace.
Random seed generator.