/usr/include/boost/random/bernoulli_distribution.hpp is in libboost1.55-dev 1.55.0-1.
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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 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 | /* boost random/bernoulli_distribution.hpp header file
*
* Copyright Jens Maurer 2000-2001
* Copyright Steven Watanabe 2011
* 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: bernoulli_distribution.hpp 71018 2011-04-05 21:27:52Z steven_watanabe $
*
* Revision history
* 2001-02-18 moved to individual header files
*/
#ifndef BOOST_RANDOM_BERNOULLI_DISTRIBUTION_HPP
#define BOOST_RANDOM_BERNOULLI_DISTRIBUTION_HPP
#include <iosfwd>
#include <boost/assert.hpp>
#include <boost/random/detail/config.hpp>
#include <boost/random/detail/operators.hpp>
namespace boost {
namespace random {
/**
* Instantiations of class template \bernoulli_distribution model a
* \random_distribution. Such a random distribution produces bool values
* distributed with probabilities P(true) = p and P(false) = 1-p. p is
* the parameter of the distribution.
*/
template<class RealType = double>
class bernoulli_distribution
{
public:
// In principle, this could work with both integer and floating-point
// types. Generating floating-point random numbers in the first
// place is probably more expensive, so use integer as input.
typedef int input_type;
typedef bool result_type;
class param_type
{
public:
typedef bernoulli_distribution distribution_type;
/**
* Constructs the parameters of the distribution.
*
* Requires: 0 <= p <= 1
*/
explicit param_type(RealType p_arg = RealType(0.5))
: _p(p_arg)
{
BOOST_ASSERT(_p >= 0);
BOOST_ASSERT(_p <= 1);
}
/** Returns the p parameter of the distribution. */
RealType p() const { return _p; }
/** Writes the parameters to a std::ostream. */
BOOST_RANDOM_DETAIL_OSTREAM_OPERATOR(os, param_type, parm)
{
os << parm._p;
return os;
}
/** Reads the parameters from a std::istream. */
BOOST_RANDOM_DETAIL_ISTREAM_OPERATOR(is, param_type, parm)
{
is >> parm._p;
return is;
}
/** Returns true if the two sets of parameters are equal. */
BOOST_RANDOM_DETAIL_EQUALITY_OPERATOR(param_type, lhs, rhs)
{ return lhs._p == rhs._p; }
/** Returns true if the two sets of parameters are different. */
BOOST_RANDOM_DETAIL_INEQUALITY_OPERATOR(param_type)
private:
RealType _p;
};
/**
* Constructs a \bernoulli_distribution object.
* p is the parameter of the distribution.
*
* Requires: 0 <= p <= 1
*/
explicit bernoulli_distribution(const RealType& p_arg = RealType(0.5))
: _p(p_arg)
{
BOOST_ASSERT(_p >= 0);
BOOST_ASSERT(_p <= 1);
}
/**
* Constructs \bernoulli_distribution from its parameters
*/
explicit bernoulli_distribution(const param_type& parm)
: _p(parm.p()) {}
// compiler-generated copy ctor and assignment operator are fine
/**
* Returns: The "p" parameter of the distribution.
*/
RealType p() const { return _p; }
/** Returns the smallest value that the distribution can produce. */
bool min BOOST_PREVENT_MACRO_SUBSTITUTION () const
{ return false; }
/** Returns the largest value that the distribution can produce. */
bool max BOOST_PREVENT_MACRO_SUBSTITUTION () const
{ return true; }
/** Returns the parameters of the distribution. */
param_type param() const { return param_type(_p); }
/** Sets the parameters of the distribution. */
void param(const param_type& parm) { _p = parm.p(); }
/**
* Effects: Subsequent uses of the distribution do not depend
* on values produced by any engine prior to invoking reset.
*/
void reset() { }
/**
* Returns: a random variate distributed according to the
* \bernoulli_distribution.
*/
template<class Engine>
bool operator()(Engine& eng) const
{
if(_p == RealType(0))
return false;
else
return RealType(eng() - (eng.min)()) <= _p * RealType((eng.max)()-(eng.min)());
}
/**
* Returns: a random variate distributed according to the
* \bernoulli_distribution with parameters specified by param.
*/
template<class Engine>
bool operator()(Engine& eng, const param_type& parm) const
{
return bernoulli_distribution(parm)(eng);
}
/**
* Writes the parameters of the distribution to a @c std::ostream.
*/
BOOST_RANDOM_DETAIL_OSTREAM_OPERATOR(os, bernoulli_distribution, bd)
{
os << bd._p;
return os;
}
/**
* Reads the parameters of the distribution from a @c std::istream.
*/
BOOST_RANDOM_DETAIL_ISTREAM_OPERATOR(is, bernoulli_distribution, bd)
{
is >> bd._p;
return is;
}
/**
* Returns true iff the two distributions will produce identical
* sequences of values given equal generators.
*/
BOOST_RANDOM_DETAIL_EQUALITY_OPERATOR(bernoulli_distribution, lhs, rhs)
{ return lhs._p == rhs._p; }
/**
* Returns true iff the two distributions will produce different
* sequences of values given equal generators.
*/
BOOST_RANDOM_DETAIL_INEQUALITY_OPERATOR(bernoulli_distribution)
private:
RealType _p;
};
} // namespace random
using random::bernoulli_distribution;
} // namespace boost
#endif // BOOST_RANDOM_BERNOULLI_DISTRIBUTION_HPP
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