/usr/include/boost/random/bernoulli_distribution.hpp is in libboost1.46-dev 1.46.1-7ubuntu3.
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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 | /* boost random/bernoulli_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: bernoulli_distribution.hpp 60755 2010-03-22 00:45:06Z 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 <cassert>
#include <iostream>
#include <boost/random/detail/config.hpp>
namespace boost {
/**
* 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;
/**
* 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)
{
assert(_p >= 0);
assert(_p <= 1);
}
// compiler-generated copy ctor and assignment operator are fine
/**
* Returns: The "p" parameter of the distribution.
*/
RealType p() const { return _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>
result_type operator()(Engine& eng)
{
if(_p == RealType(0))
return false;
else
return RealType(eng() - (eng.min)()) <= _p * RealType((eng.max)()-(eng.min)());
}
#ifndef BOOST_RANDOM_NO_STREAM_OPERATORS
/**
* Writes the parameters of the distribution to a @c std::ostream.
*/
template<class CharT, class Traits>
friend std::basic_ostream<CharT,Traits>&
operator<<(std::basic_ostream<CharT,Traits>& os, const bernoulli_distribution& bd)
{
os << bd._p;
return os;
}
/**
* Reads the parameters of the distribution from a @c std::istream.
*/
template<class CharT, class Traits>
friend std::basic_istream<CharT,Traits>&
operator>>(std::basic_istream<CharT,Traits>& is, bernoulli_distribution& bd)
{
is >> std::ws >> bd._p;
return is;
}
#endif
private:
RealType _p;
};
} // namespace boost
#endif // BOOST_RANDOM_BERNOULLI_DISTRIBUTION_HPP
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