/* 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 60755 2010-03-22 00:45:06Z steven_watanabe $
+ * $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 <cassert>
-#include <iostream>
+#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
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
+ // 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;
+ RealType _p;
};
+} // namespace random
+
+using random::bernoulli_distribution;
+
} // namespace boost
#endif // BOOST_RANDOM_BERNOULLI_DISTRIBUTION_HPP
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