/usr/include/boost/random/geometric_distribution.hpp is in libboost1.46-dev 1.46.1-7ubuntu3.
This file is owned by root:root, with mode 0o644.
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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 | /* boost random/geometric_distribution.hpp header file
*
* Copyright Jens Maurer 2000-2001
* Distributed under the Boost Software License, Version 1.0. (See
* accompanying file LICENSE_1_0.txt or copy at
* http://www.boost.org/LICENSE_1_0.txt)
*
* See http://www.boost.org for most recent version including documentation.
*
* $Id: geometric_distribution.hpp 60755 2010-03-22 00:45:06Z steven_watanabe $
*
* Revision history
* 2001-02-18 moved to individual header files
*/
#ifndef BOOST_RANDOM_GEOMETRIC_DISTRIBUTION_HPP
#define BOOST_RANDOM_GEOMETRIC_DISTRIBUTION_HPP
#include <boost/config/no_tr1/cmath.hpp> // std::log
#include <cassert>
#include <iostream>
#include <boost/random/detail/config.hpp>
#include <boost/random/uniform_01.hpp>
namespace boost {
#if defined(__GNUC__) && (__GNUC__ < 3)
// Special gcc workaround: gcc 2.95.x ignores using-declarations
// in template classes (confirmed by gcc author Martin v. Loewis)
using std::log;
#endif
/**
* An instantiation of the class template @c geometric_distribution models
* a \random_distribution. The distribution produces positive
* integers which are the number of bernoulli trials
* with probability @c p required to get one that fails.
*
* For the geometric distribution, \f$p(i) = (1-p) p^{i-1}\f$.
*/
template<class IntType = int, class RealType = double>
class geometric_distribution
{
public:
typedef RealType input_type;
typedef IntType result_type;
/**
* Contructs a new geometric_distribution with the paramter @c p.
*
* Requires: 0 < p < 1
*/
explicit geometric_distribution(const RealType& p = RealType(0.5))
: _p(p)
{
assert(RealType(0) < _p && _p < RealType(1));
init();
}
// compiler-generated copy ctor and assignment operator are fine
/**
* Returns: the distribution parameter @c p
*/
RealType p() const { return _p; }
void reset() { }
template<class Engine>
result_type operator()(Engine& eng)
{
#ifndef BOOST_NO_STDC_NAMESPACE
using std::log;
using std::floor;
#endif
return IntType(floor(log(RealType(1)-eng()) / _log_p)) + IntType(1);
}
#ifndef BOOST_RANDOM_NO_STREAM_OPERATORS
template<class CharT, class Traits>
friend std::basic_ostream<CharT,Traits>&
operator<<(std::basic_ostream<CharT,Traits>& os, const geometric_distribution& gd)
{
os << gd._p;
return os;
}
template<class CharT, class Traits>
friend std::basic_istream<CharT,Traits>&
operator>>(std::basic_istream<CharT,Traits>& is, geometric_distribution& gd)
{
is >> std::ws >> gd._p;
gd.init();
return is;
}
#endif
private:
/// \cond hide_private_functions
void init()
{
#ifndef BOOST_NO_STDC_NAMESPACE
using std::log;
#endif
_log_p = log(_p);
}
/// \endcond
RealType _p;
RealType _log_p;
};
} // namespace boost
#endif // BOOST_RANDOM_GEOMETRIC_DISTRIBUTION_HPP
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