--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/ossrv_pub/boost_apis/boost/random/normal_distribution.hpp Tue Feb 02 02:01:42 2010 +0200
@@ -0,0 +1,111 @@
+/* boost random/normal_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: normal_distribution.hpp,v 1.20 2004/07/27 03:43:32 dgregor Exp $
+ *
+ * Revision history
+ * 2001-02-18 moved to individual header files
+ */
+
+#ifndef BOOST_RANDOM_NORMAL_DISTRIBUTION_HPP
+#define BOOST_RANDOM_NORMAL_DISTRIBUTION_HPP
+
+#include <cmath>
+#include <cassert>
+#include <iostream>
+#include <boost/limits.hpp>
+#include <boost/static_assert.hpp>
+
+namespace boost {
+
+// deterministic polar method, uses trigonometric functions
+template<class RealType = double>
+class normal_distribution
+{
+public:
+ typedef RealType input_type;
+ typedef RealType result_type;
+
+#if !defined(BOOST_NO_LIMITS_COMPILE_TIME_CONSTANTS) && !(defined(BOOST_MSVC) && BOOST_MSVC <= 1300)
+ BOOST_STATIC_ASSERT(!std::numeric_limits<RealType>::is_integer);
+#endif
+
+ explicit normal_distribution(const result_type& mean = result_type(0),
+ const result_type& sigma = result_type(1))
+ : _mean(mean), _sigma(sigma), _valid(false)
+ {
+ assert(sigma >= result_type(0));
+ }
+
+ // compiler-generated copy constructor is NOT fine, need to purge cache
+ normal_distribution(const normal_distribution& other)
+ : _mean(other._mean), _sigma(other._sigma), _valid(false)
+ {
+ }
+
+ // compiler-generated copy ctor and assignment operator are fine
+
+ RealType mean() const { return _mean; }
+ RealType sigma() const { return _sigma; }
+
+ void reset() { _valid = false; }
+
+ template<class Engine>
+ result_type operator()(Engine& eng)
+ {
+#ifndef BOOST_NO_STDC_NAMESPACE
+ // allow for Koenig lookup
+ using std::sqrt; using std::log; using std::sin; using std::cos;
+#endif
+ if(!_valid) {
+ _r1 = eng();
+ _r2 = eng();
+ _cached_rho = sqrt(-result_type(2) * log(result_type(1)-_r2));
+ _valid = true;
+ } else {
+ _valid = false;
+ }
+ // Can we have a boost::mathconst please?
+ const result_type pi = result_type(3.14159265358979323846);
+
+ return _cached_rho * (_valid ?
+ cos(result_type(2)*pi*_r1) :
+ sin(result_type(2)*pi*_r1))
+ * _sigma + _mean;
+ }
+
+#if !defined(BOOST_NO_OPERATORS_IN_NAMESPACE) && !defined(BOOST_NO_MEMBER_TEMPLATE_FRIENDS)
+ template<class CharT, class Traits>
+ friend std::basic_ostream<CharT,Traits>&
+ operator<<(std::basic_ostream<CharT,Traits>& os, const normal_distribution& nd)
+ {
+ os << nd._mean << " " << nd._sigma << " "
+ << nd._valid << " " << nd._cached_rho << " " << nd._r1;
+ return os;
+ }
+
+ template<class CharT, class Traits>
+ friend std::basic_istream<CharT,Traits>&
+ operator>>(std::basic_istream<CharT,Traits>& is, normal_distribution& nd)
+ {
+ is >> std::ws >> nd._mean >> std::ws >> nd._sigma
+ >> std::ws >> nd._valid >> std::ws >> nd._cached_rho
+ >> std::ws >> nd._r1;
+ return is;
+ }
+#endif
+private:
+ result_type _mean, _sigma;
+ result_type _r1, _r2, _cached_rho;
+ bool _valid;
+};
+
+} // namespace boost
+
+#endif // BOOST_RANDOM_NORMAL_DISTRIBUTION_HPP