diff DEPENDENCIES/generic/include/boost/random/bernoulli_distribution.hpp @ 16:2665513ce2d3

Add boost headers
author Chris Cannam
date Tue, 05 Aug 2014 11:11:38 +0100
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children c530137014c0
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--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/DEPENDENCIES/generic/include/boost/random/bernoulli_distribution.hpp	Tue Aug 05 11:11:38 2014 +0100
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+/* 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