Subject: [Boost-commit] svn:boost r63180 - in trunk: boost/random libs/random/doc libs/random/test
From: steven_at_[hidden]
Date: 2010-06-21 00:03:57
Author: steven_watanabe
Date: 2010-06-21 00:03:55 EDT (Mon, 21 Jun 2010)
New Revision: 63180
URL: http://svn.boost.org/trac/boost/changeset/63180
Log:
Implement discrete_distribution. Fixes #920.
Added:
trunk/boost/random/discrete_distribution.hpp (contents, props changed)
trunk/libs/random/test/test_discrete.cpp (contents, props changed)
trunk/libs/random/test/test_discrete_distribution.cpp (contents, props changed)
Text files modified:
trunk/libs/random/doc/Jamfile.v2 | 1 +
trunk/libs/random/doc/distributions.qbk | 1 +
trunk/libs/random/doc/random.qbk | 1 +
trunk/libs/random/test/Jamfile.v2 | 2 ++
4 files changed, 5 insertions(+), 0 deletions(-)
Added: trunk/boost/random/discrete_distribution.hpp
==============================================================================
--- (empty file)
+++ trunk/boost/random/discrete_distribution.hpp 2010-06-21 00:03:55 EDT (Mon, 21 Jun 2010)
@@ -0,0 +1,494 @@
+// discrete_distribution.hpp
+//
+// Copyright (c) 2009-2010
+// Steven Watanabe
+//
+// 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)
+
+#ifndef BOOST_RANDOM_DISCRETE_DISTRIBUTION_HPP_INCLUDED
+#define BOOST_RANDOM_DISCRETE_DISTRIBUTION_HPP_INCLUDED
+
+#include <vector>
+#include <cassert>
+#include <limits>
+#include <numeric>
+#include <utility>
+#include <iterator>
+#include <boost/random/uniform_01.hpp>
+#include <boost/random/uniform_int.hpp>
+#include <boost/random/detail/config.hpp>
+
+#ifndef BOOST_NO_INITIALIZER_LISTS
+#include <initializer_list>
+#endif
+
+#include <boost/range/begin.hpp>
+#include <boost/range/end.hpp>
+
+namespace boost {
+namespace random {
+
+/**
+ * The class @c discrete_distribution models a \random_distribution.
+ * It produces integers in the range [0, n) with the probability
+ * of producing each value is specified by the parameters of the
+ * distribution.
+ */
+template<class IntType = int, class WeightType = double>
+class discrete_distribution {
+public:
+ typedef WeightType input_type;
+ typedef IntType result_type;
+
+ class param_type {
+ public:
+ /**
+ * Constructs a @c param_type object, representing a distribution
+ * with \f$p(0) = 1\f$ and \f$p(k|k>0) = 0\f$.
+ */
+ param_type() : _probabilities(1, static_cast<WeightType>(1)) {}
+ /**
+ * If @c first == @c last, equivalent to the default constructor.
+ * Otherwise, the values of the range represent weights for the
+ * possible values of the distribution.
+ */
+ template<class Iter>
+ param_type(Iter first, Iter last) : _probabilities(first, last)
+ {
+ normalize();
+ }
+#ifndef BOOST_NO_INITIALIZER_LISTS
+ /**
+ * If wl.size() == 0, equivalent to the default constructor.
+ * Otherwise, the values of the @c initializer_list represent
+ * weights for the possible values of the distribution.
+ */
+ param_type(const std::initializer_list<WeightType>& wl)
+ : _probabilities(wl)
+ {
+ normalize();
+ }
+#endif
+ /**
+ * If the range is empty, equivalent to the default constructor.
+ * Otherwise, the elements of the range represent
+ * weights for the possible values of the distribution.
+ */
+ template<class Range>
+ explicit param_type(const Range& range)
+ : _probabilities(boost::begin(range), boost::end(range))
+ {
+ normalize();
+ }
+
+ /**
+ * If nw is zero, equivalent to the default constructor.
+ * Otherwise, the range of the distribution is [0, nw),
+ * and the weights are found by calling fw with values
+ * evenly distributed between \f$\mbox{xmin} + \delta/2\f$ and
+ * \f$\mbox{xmax} - \delta/2\f$, where
+ * \f$\delta = (\mbox{xmax} - \mbox{xmin})/\mbox{nw}\f$.
+ */
+ template<class Func>
+ param_type(std::size_t nw, double xmin, double xmax, Func fw)
+ {
+ std::size_t n = (nw == 0) ? 1 : nw;
+ double delta = (xmax - xmin) / n;
+ assert(delta > 0);
+ for(std::size_t k = 0; k < n; ++k) {
+ _probabilities.push_back(fw(xmin + k*delta + delta/2));
+ }
+ normalize();
+ }
+
+ /**
+ * Returns a vector containing the probabilities of each possible
+ * value of the distribution.
+ */
+ std::vector<WeightType> probabilities() const
+ {
+ return _probabilities;
+ }
+
+#ifndef BOOST_RANDOM_NO_STREAM_OPERATORS
+ /** Writes the parameters to a @c std::ostream. */
+ template<class CharT, class Traits>
+ friend std::basic_ostream<CharT, Traits>&
+ operator<<(std::basic_ostream<CharT, Traits>& os,
+ const param_type& parm)
+ {
+ typename std::vector<WeightType>::const_iterator
+ iter = parm._probabilities.begin(),
+ end = parm._probabilities.end();
+ os << '[';
+ if(iter != end) {
+ os << *iter;
+ ++iter;
+ for(; iter != end; ++iter)
+ {
+ os << ' ' << *iter;
+ }
+ }
+ os << ']';
+ return os;
+ }
+
+ /** Reads the parameters from a @c std::istream. */
+ template<class CharT, class Traits>
+ friend std::basic_istream<CharT, Traits>&
+ operator>>(std::basic_istream<CharT, Traits>& is, param_type& parm)
+ {
+ std::vector<WeightType> result;
+ char ch;
+ if(!(is >> ch)) {
+ return is;
+ }
+ if(ch != '[') {
+ is.putback(ch);
+ is.setstate(std::ios_base::failbit);
+ return is;
+ }
+ WeightType val;
+ while(is >> std::ws >> val) {
+ result.push_back(val);
+ }
+ if(is.fail()) {
+ is.clear();
+ if(!(is >> ch)) {
+ return is;
+ }
+ if(ch != ']') {
+ is.putback(ch);
+ is.setstate(std::ios_base::failbit);
+ }
+ }
+ parm._probabilities.swap(result);
+ return is;
+ }
+#endif
+
+ /** Returns true if the two sets of parameters are the same. */
+ friend bool operator==(const param_type& lhs, const param_type& rhs)
+ {
+ return lhs._probabilities == rhs._probabilities;
+ }
+ /** Returns true if the two sets of parameters are different. */
+ friend bool operator!=(const param_type& lhs, const param_type& rhs)
+ {
+ return !(lhs == rhs);
+ }
+ private:
+ /// @cond
+ friend class discrete_distribution;
+ explicit param_type(const discrete_distribution& dist)
+ : _probabilities(dist.probabilities())
+ {}
+ void normalize()
+ {
+ WeightType sum =
+ std::accumulate(_probabilities.begin(), _probabilities.end(),
+ static_cast<WeightType>(0));
+ for(typename std::vector<WeightType>::iterator
+ iter = _probabilities.begin(),
+ end = _probabilities.end();
+ iter != end; ++iter)
+ {
+ *iter /= sum;
+ }
+ }
+ std::vector<WeightType> _probabilities;
+ /// @endcond
+ };
+
+ /**
+ * Creates a new @c discrete_distribution object that has
+ * \f$p(0) = 1\f$ and \f$p(i|i>0) = 0\f$.
+ */
+ discrete_distribution()
+ {
+ _alias_table.push_back(std::make_pair(static_cast<WeightType>(1),
+ static_cast<IntType>(0)));
+ }
+ /**
+ * Constructs a discrete_distribution from an iterator range.
+ * If @c first == @c last, equivalent to the default constructor.
+ * Otherwise, the values of the range represent weights for the
+ * possible values of the distribution.
+ */
+ template<class Iter>
+ discrete_distribution(Iter first, Iter last)
+ {
+ init(first, last);
+ }
+#ifndef BOOST_NO_INITIALIZER_LISTS
+ /**
+ * Constructs a @c discrete_distribution from a @c std::initializer_list.
+ * If the @c initializer_list is empty, equivalent to the default
+ * constructor. Otherwise, the values of the @c initializer_list
+ * represent weights for the possible values of the distribution.
+ * For example, given the distribution
+ *
+ * @code
+ * discrete_distribution<> dist{1, 4, 5};
+ * @endcode
+ *
+ * The probability of a 0 is 1/10, the probability of a 1 is 2/5,
+ * the probability of a 2 is 1/2, and no other values are possible.
+ */
+ discrete_distribution(std::initializer_list<WeightType> wl)
+ {
+ init(wl.begin(), wl.end());
+ }
+#endif
+ /**
+ * Constructs a discrete_distribution from a Boost.Range range.
+ * If the range is empty, equivalent to the default constructor.
+ * Otherwise, the values of the range represent weights for the
+ * possible values of the distribution.
+ */
+ template<class Range>
+ explicit discrete_distribution(const Range& range)
+ {
+ init(boost::begin(range), boost::end(range));
+ }
+ /**
+ * Constructs a discrete_distribution that approximates a function.
+ * If nw is zero, equivalent to the default constructor.
+ * Otherwise, the range of the distribution is [0, nw),
+ * and the weights are found by calling fw with values
+ * evenly distributed between \f$\mbox{xmin} + \delta/2\f$ and
+ * \f$\mbox{xmax} - \delta/2\f$, where
+ * \f$\delta = (\mbox{xmax} - \mbox{xmin})/\mbox{nw}\f$.
+ */
+ template<class Func>
+ discrete_distribution(std::size_t nw, double xmin, double xmax, Func fw)
+ {
+ std::size_t n = (nw == 0) ? 1 : nw;
+ double delta = (xmax - xmin) / n;
+ assert(delta > 0);
+ std::vector<WeightType> weights;
+ for(std::size_t k = 0; k < n; ++k) {
+ weights.push_back(fw(xmin + k*delta + delta/2));
+ }
+ init(weights.begin(), weights.end());
+ }
+ /**
+ * Constructs a discrete_distribution from its parameters.
+ */
+ explicit discrete_distribution(const param_type& parm)
+ {
+ param(parm);
+ }
+
+ /**
+ * Returns a value distributed according to the parameters of the
+ * discrete_distribution.
+ */
+ template<class URNG>
+ IntType operator()(URNG& urng) const {
+ assert(!_alias_table.empty());
+ WeightType test = uniform_01<WeightType>()(urng);
+ IntType result = uniform_int<IntType>((min)(), (max)())(urng);
+ if(test < _alias_table[result].first) {
+ return result;
+ } else {
+ return(_alias_table[result].second);
+ }
+ }
+
+ /**
+ * Returns a value distributed according to the parameters
+ * specified by parm.
+ */
+ template<class URNG>
+ IntType operator()(URNG& urng, const param_type& parm) const
+ {
+ while(true) {
+ WeightType val = uniform_01<WeightType>()(urng);
+ WeightType sum = 0;
+ std::size_t result = 0;
+ for(typename std::vector<WeightType>::const_iterator
+ iter = parm._probabilities.begin(),
+ end = parm._probabilities.end();
+ iter != end; ++iter, ++result)
+ {
+ sum += *iter;
+ if(sum > val) {
+ return result;
+ }
+ }
+ }
+ }
+
+ /** Returns the smallest value that the distribution can produce. */
+ result_type min BOOST_PREVENT_MACRO_SUBSTITUTION () const { return 0; }
+ /** Returns the largest value that the distribution can produce. */
+ result_type max BOOST_PREVENT_MACRO_SUBSTITUTION () const
+ { return static_cast<result_type>(_alias_table.size() - 1); }
+
+ /**
+ * Returns a vector containing the probabilities of each
+ * value of the distribution. For example, given
+ *
+ * @code
+ * discrete_distribution<> dist = { 1, 4, 5 };
+ * std::vector<double> p = dist.param();
+ * @endcode
+ *
+ * the vector, p will contain {0.1, 0.4, 0.5}.
+ */
+ std::vector<WeightType> probabilities() const
+ {
+ std::vector<WeightType> result(_alias_table.size());
+ const WeightType mean =
+ static_cast<WeightType>(1) / _alias_table.size();
+ std::size_t i = 0;
+ for(typename alias_table_t::const_iterator
+ iter = _alias_table.begin(),
+ end = _alias_table.end();
+ iter != end; ++iter, ++i)
+ {
+ WeightType val = iter->first * mean;
+ result[i] += val;
+ result[iter->second] += mean - val;
+ }
+ return(result);
+ }
+
+ /** Returns the parameters of the distribution. */
+ param_type param() const
+ {
+ return param_type(*this);
+ }
+ /** Sets the parameters of the distribution. */
+ void param(const param_type& parm)
+ {
+ init(parm._probabilities.begin(), parm._probabilities.end());
+ }
+
+ /**
+ * Effects: Subsequent uses of the distribution do not depend
+ * on values produced by any engine prior to invoking reset.
+ */
+ void reset() {}
+
+#ifndef BOOST_RANDOM_NO_STREAM_OPERATORS
+ /** Writes a 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 discrete_distribution& dd)
+ {
+ os << dd.param();
+ return os;
+ }
+
+ /** Reads a distribution from a @c std::istream */
+ template<class CharT, class Traits>
+ friend std::basic_istream<CharT, Traits>&
+ operator>>(std::basic_istream<CharT, Traits>& is, discrete_distribution& dd)
+ {
+ param_type parm;
+ if(is >> parm) {
+ dd.param(parm);
+ }
+ return is;
+ }
+#endif
+
+ /**
+ * Returns true if the two distributions will return the
+ * same sequence of values, when passed equal generators.
+ */
+ friend bool operator==(const discrete_distribution& lhs,
+ const discrete_distribution& rhs)
+ {
+ return lhs._alias_table == rhs._alias_table;
+ }
+ /**
+ * Returns true if the two distributions may return different
+ * sequences of values, when passed equal generators.
+ */
+ friend bool operator!=(const discrete_distribution& lhs,
+ const discrete_distribution& rhs)
+ {
+ return !(lhs == rhs);
+ }
+
+private:
+
+ /// @cond
+
+ template<class Iter>
+ void init(Iter first, Iter last, std::input_iterator_tag)
+ {
+ std::vector<WeightType> temp(first, last);
+ init(temp.begin(), temp.end());
+ }
+ template<class Iter>
+ void init(Iter first, Iter last, std::forward_iterator_tag)
+ {
+ std::vector<std::pair<WeightType, IntType> > below_average;
+ std::vector<std::pair<WeightType, IntType> > above_average;
+ std::size_t size = std::distance(first, last);
+ WeightType weight_sum =
+ std::accumulate(first, last, static_cast<WeightType>(0));
+ WeightType weight_average = weight_sum / size;
+ std::size_t i = 0;
+ for(; first != last; ++first, ++i) {
+ WeightType val = *first / weight_average;
+ std::pair<WeightType, IntType> elem(val, static_cast<IntType>(i));
+ if(val < static_cast<WeightType>(1)) {
+ below_average.push_back(elem);
+ } else {
+ above_average.push_back(elem);
+ }
+ }
+
+ _alias_table.resize(size);
+ typename alias_table_t::iterator
+ b_iter = below_average.begin(),
+ b_end = below_average.end(),
+ a_iter = above_average.begin(),
+ a_end = above_average.end()
+ ;
+ while(b_iter != b_end && a_iter != a_end) {
+ _alias_table[b_iter->second] =
+ std::make_pair(b_iter->first, a_iter->second);
+ a_iter->first -= (static_cast<WeightType>(1) - b_iter->first);
+ if(a_iter->first < static_cast<WeightType>(1)) {
+ *b_iter = *a_iter++;
+ } else {
+ ++b_iter;
+ }
+ }
+ for(; b_iter != b_end; ++b_iter) {
+ _alias_table[b_iter->second].first = static_cast<WeightType>(1);
+ }
+ for(; a_iter != a_end; ++a_iter) {
+ _alias_table[a_iter->second].first = static_cast<WeightType>(1);
+ }
+ }
+ template<class Iter>
+ void init(Iter first, Iter last)
+ {
+ if(first == last) {
+ _alias_table.clear();
+ _alias_table.push_back(std::make_pair(static_cast<WeightType>(1),
+ static_cast<IntType>(0)));
+ } else {
+ typename std::iterator_traits<Iter>::iterator_category category;
+ init(first, last, category);
+ }
+ }
+ typedef std::vector<std::pair<WeightType, IntType> > alias_table_t;
+ alias_table_t _alias_table;
+ /// @endcond
+};
+
+}
+}
+
+#endif
Modified: trunk/libs/random/doc/Jamfile.v2
==============================================================================
--- trunk/libs/random/doc/Jamfile.v2 (original)
+++ trunk/libs/random/doc/Jamfile.v2 2010-06-21 00:03:55 EDT (Mon, 21 Jun 2010)
@@ -20,6 +20,7 @@
binomial_distribution
cauchy_distribution
discard_block
+ discrete_distribution
exponential_distribution
gamma_distribution
geometric_distribution
Modified: trunk/libs/random/doc/distributions.qbk
==============================================================================
--- trunk/libs/random/doc/distributions.qbk (original)
+++ trunk/libs/random/doc/distributions.qbk 2010-06-21 00:03:55 EDT (Mon, 21 Jun 2010)
@@ -44,6 +44,7 @@
[tossing a coin 20 times and counting how many
front sides are shown]]
[[__cauchy_distribution][cauchy distribution][-]]
+ [[__discrete_distribution][discrete distribution with specific probabilities][rolling an unfair die]]
[[__gamma_distribution][gamma distribution][-]]
[[__poisson_distribution][poisson distribution]
[counting the number of alpha particles emitted
Modified: trunk/libs/random/doc/random.qbk
==============================================================================
--- trunk/libs/random/doc/random.qbk (original)
+++ trunk/libs/random/doc/random.qbk 2010-06-21 00:03:55 EDT (Mon, 21 Jun 2010)
@@ -64,6 +64,7 @@
[def __bernoulli_distribution [classref boost::bernoulli_distribution bernoulli_distribution]]
[def __binomial_distribution [classref boost::random::binomial_distribution binomial_distribution]]
[def __cauchy_distribution [classref boost::cauchy_distribution cauchy_distribution]]
+[def __discrete_distribution [classref boost::random::discrete_distribution discrete_distribution]]
[def __gamma_distribution [classref boost::gamma_distribution gamma_distribution]]
[def __poisson_distribution [classref boost::random::poisson_distribution poisson_distribution]]
[def __geometric_distribution [classref boost::geometric_distribution geometric_distribution]]
Modified: trunk/libs/random/test/Jamfile.v2
==============================================================================
--- trunk/libs/random/test/Jamfile.v2 (original)
+++ trunk/libs/random/test/Jamfile.v2 2010-06-21 00:03:55 EDT (Mon, 21 Jun 2010)
@@ -45,6 +45,8 @@
run test_binomial_distribution.cpp /boost//unit_test_framework ;
run test_poisson.cpp ;
run test_poisson_distribution.cpp /boost//unit_test_framework ;
+run test_discrete.cpp ;
+run test_discrete_distribution.cpp /boost//unit_test_framework ;
# run nondet_random_speed.cpp ;
# run random_device.cpp ;
Added: trunk/libs/random/test/test_discrete.cpp
==============================================================================
--- (empty file)
+++ trunk/libs/random/test/test_discrete.cpp 2010-06-21 00:03:55 EDT (Mon, 21 Jun 2010)
@@ -0,0 +1,123 @@
+/* test_poisson.cpp
+ *
+ * Copyright Steven Watanabe 2010
+ * 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)
+ *
+ * $Id$
+ *
+ */
+
+#include <boost/random/discrete_distribution.hpp>
+#include <boost/random/uniform_int.hpp>
+#include <boost/random/mersenne_twister.hpp>
+#include <boost/lexical_cast.hpp>
+#include <boost/exception/diagnostic_information.hpp>
+#include <vector>
+#include <iostream>
+#include <numeric>
+
+#include "chi_squared_test.hpp"
+
+bool do_test(int n, long long max) {
+ std::cout << "running discrete(p0, p1, ..., p" << n-1 << ")" << " " << max << " times: " << std::flush;
+
+ std::vector<double> expected;
+ {
+ boost::mt19937 egen;
+ for(int i = 0; i < n; ++i) {
+ expected.push_back(egen());
+ }
+ double sum = std::accumulate(expected.begin(), expected.end(), 0.0);
+ for(std::vector<double>::iterator iter = expected.begin(), end = expected.end(); iter != end; ++iter) {
+ *iter /= sum;
+ }
+ }
+
+ boost::random::discrete_distribution<> dist(expected);
+ boost::mt19937 gen;
+ std::vector<long long> results(expected.size());
+ for(long long i = 0; i < max; ++i) {
+ ++results[dist(gen)];
+ }
+
+ long long sum = std::accumulate(results.begin(), results.end(), 0ll);
+ if(sum != max) {
+ std::cout << "*** Failed: incorrect total: " << sum << " ***" << std::endl;
+ return false;
+ }
+ double chsqr = chi_squared_test(results, expected, max);
+
+ bool result = chsqr < 0.99;
+ const char* err = result? "" : "*";
+ std::cout << std::setprecision(17) << chsqr << err << std::endl;
+
+ std::cout << std::setprecision(6);
+
+ return result;
+}
+
+bool do_tests(int repeat, int max_n, long long trials) {
+ boost::mt19937 gen;
+ boost::uniform_int<> idist(1, max_n);
+ int errors = 0;
+ for(int i = 0; i < repeat; ++i) {
+ if(!do_test(idist(gen), trials)) {
+ ++errors;
+ }
+ }
+ if(errors != 0) {
+ std::cout << "*** " << errors << " errors detected ***" << std::endl;
+ }
+ return errors == 0;
+}
+
+int usage() {
+ std::cerr << "Usage: test_discrete -r <repeat> -n <max n> -t <trials>" << std::endl;
+ return 2;
+}
+
+template<class T>
+bool handle_option(int& argc, char**& argv, char opt, T& value) {
+ if(argv[0][1] == opt && argc > 1) {
+ --argc;
+ ++argv;
+ value = boost::lexical_cast<T>(argv[0]);
+ return true;
+ } else {
+ return false;
+ }
+}
+
+int main(int argc, char** argv) {
+ int repeat = 10;
+ int max_n = 100000;
+ long long trials = 1000000ll;
+
+ if(argc > 0) {
+ --argc;
+ ++argv;
+ }
+ while(argc > 0) {
+ if(argv[0][0] != '-') return usage();
+ else if(!handle_option(argc, argv, 'r', repeat)
+ && !handle_option(argc, argv, 'n', max_n)
+ && !handle_option(argc, argv, 't', trials)) {
+ return usage();
+ }
+ --argc;
+ ++argv;
+ }
+
+ try {
+ if(do_tests(repeat, max_n, trials)) {
+ return 0;
+ } else {
+ return EXIT_FAILURE;
+ }
+ } catch(...) {
+ std::cerr << boost::current_exception_diagnostic_information() << std::endl;
+ return EXIT_FAILURE;
+ }
+}
Added: trunk/libs/random/test/test_discrete_distribution.cpp
==============================================================================
--- (empty file)
+++ trunk/libs/random/test/test_discrete_distribution.cpp 2010-06-21 00:03:55 EDT (Mon, 21 Jun 2010)
@@ -0,0 +1,163 @@
+/* test_discrete_distribution.cpp
+ *
+ * Copyright Steven Watanabe 2010
+ * 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)
+ *
+ * $Id$
+ *
+ */
+
+#include <boost/random/discrete_distribution.hpp>
+#include <boost/random/linear_congruential.hpp>
+#include <boost/assign/list_of.hpp>
+#include <sstream>
+#include <vector>
+
+#define BOOST_TEST_MAIN
+#include <boost/test/unit_test.hpp>
+
+struct gen {
+ double operator()(double arg) {
+ if(arg < 100) return 100;
+ else if(arg < 103) return 1;
+ else if(arg < 107) return 2;
+ else if(arg < 111) return 1;
+ else if(arg < 114) return 4;
+ else return 100;
+ }
+};
+
+#define CHECK_PROBABILITIES(actual, expected) \
+ do { \
+ std::vector<double> _actual = (actual); \
+ std::vector<double> _expected = (expected); \
+ BOOST_CHECK_EQUAL_COLLECTIONS( \
+ _actual.begin(), _actual.end(), \
+ _expected.begin(), _expected.end()); \
+ } while(false)
+
+using boost::assign::list_of;
+
+BOOST_AUTO_TEST_CASE(test_constructors) {
+ boost::random::discrete_distribution<> dist;
+ CHECK_PROBABILITIES(dist.probabilities(), list_of(1.0));
+
+#ifndef BOOST_NO_INITIALIZER_LISTS
+ boost::random::discrete_distribution<> dist_il = { 1, 2, 1, 4 };
+ CHECK_PROBABILITIES(dist_il.probabilities(), list_of(.125)(.25)(.125)(.5));
+#endif
+ std::vector<double> probs = boost::assign::list_of(1.0)(2.0)(1.0)(4.0);
+
+ boost::random::discrete_distribution<> dist_r(probs);
+ CHECK_PROBABILITIES(dist_r.probabilities(), list_of(.125)(.25)(.125)(.5));
+
+ boost::random::discrete_distribution<> dist_it(probs.begin(), probs.end());
+ CHECK_PROBABILITIES(dist_it.probabilities(), list_of(.125)(.25)(.125)(.5));
+
+ boost::random::discrete_distribution<> dist_fun(4, 99, 115, gen());
+ CHECK_PROBABILITIES(dist_fun.probabilities(), list_of(.125)(.25)(.125)(.5));
+
+ boost::random::discrete_distribution<> copy(dist);
+ BOOST_CHECK_EQUAL(dist, copy);
+ boost::random::discrete_distribution<> copy_r(dist_r);
+ BOOST_CHECK_EQUAL(dist_r, copy_r);
+
+ boost::random::discrete_distribution<> notpow2(3, 99, 111, gen());
+ BOOST_REQUIRE_EQUAL(notpow2.probabilities().size(), 3u);
+ BOOST_CHECK_CLOSE_FRACTION(notpow2.probabilities()[0], 0.25, 0.00000000001);
+ BOOST_CHECK_CLOSE_FRACTION(notpow2.probabilities()[1], 0.50, 0.00000000001);
+ BOOST_CHECK_CLOSE_FRACTION(notpow2.probabilities()[2], 0.25, 0.00000000001);
+ boost::random::discrete_distribution<> copy_notpow2(notpow2);
+ BOOST_CHECK_EQUAL(notpow2, copy_notpow2);
+}
+
+BOOST_AUTO_TEST_CASE(test_param) {
+ std::vector<double> probs = boost::assign::list_of(1.0)(2.0)(1.0)(4.0);
+ boost::random::discrete_distribution<> dist(probs);
+ boost::random::discrete_distribution<>::param_type param = dist.param();
+ CHECK_PROBABILITIES(param.probabilities(), list_of(.125)(.25)(.125)(.5));
+ boost::random::discrete_distribution<> copy1(param);
+ BOOST_CHECK_EQUAL(dist, copy1);
+ boost::random::discrete_distribution<> copy2;
+ copy2.param(param);
+ BOOST_CHECK_EQUAL(dist, copy2);
+
+ boost::random::discrete_distribution<>::param_type param_copy = param;
+ BOOST_CHECK_EQUAL(param, param_copy);
+ BOOST_CHECK(param == param_copy);
+ BOOST_CHECK(!(param != param_copy));
+ boost::random::discrete_distribution<>::param_type param_default;
+ CHECK_PROBABILITIES(param_default.probabilities(), list_of(1.0));
+ BOOST_CHECK(param != param_default);
+ BOOST_CHECK(!(param == param_default));
+
+#ifndef BOOST_NO_INITIALIZER_LISTS
+ boost::random::discrete_distribution<>::param_type
+ parm_il = { 1, 2, 1, 4 };
+ CHECK_PROBABILITIES(parm_il.probabilities(), list_of(.125)(.25)(.125)(.5));
+#endif
+
+ boost::random::discrete_distribution<>::param_type parm_r(probs);
+ CHECK_PROBABILITIES(parm_r.probabilities(), list_of(.125)(.25)(.125)(.5));
+
+ boost::random::discrete_distribution<>::param_type
+ parm_it(probs.begin(), probs.end());
+ CHECK_PROBABILITIES(parm_it.probabilities(), list_of(.125)(.25)(.125)(.5));
+
+ boost::random::discrete_distribution<>::param_type
+ parm_fun(4, 99, 115, gen());
+ CHECK_PROBABILITIES(parm_fun.probabilities(), list_of(.125)(.25)(.125)(.5));
+}
+
+BOOST_AUTO_TEST_CASE(test_min_max) {
+ std::vector<double> probs = boost::assign::list_of(1.0)(2.0)(1.0);
+ boost::random::discrete_distribution<> dist;
+ BOOST_CHECK_EQUAL((dist.min)(), 0);
+ BOOST_CHECK_EQUAL((dist.max)(), 0);
+ boost::random::discrete_distribution<> dist_r(probs);
+ BOOST_CHECK_EQUAL((dist_r.min)(), 0);
+ BOOST_CHECK_EQUAL((dist_r.max)(), 2);
+}
+
+BOOST_AUTO_TEST_CASE(test_comparison) {
+ std::vector<double> probs = boost::assign::list_of(1.0)(2.0)(1.0)(4.0);
+ boost::random::discrete_distribution<> dist;
+ boost::random::discrete_distribution<> dist_copy(dist);
+ boost::random::discrete_distribution<> dist_r(probs);
+ boost::random::discrete_distribution<> dist_r_copy(dist_r);
+ BOOST_CHECK(dist == dist_copy);
+ BOOST_CHECK(!(dist != dist_copy));
+ BOOST_CHECK(dist_r == dist_r_copy);
+ BOOST_CHECK(!(dist_r != dist_r_copy));
+ BOOST_CHECK(dist != dist_r);
+ BOOST_CHECK(!(dist == dist_r));
+}
+
+BOOST_AUTO_TEST_CASE(test_streaming) {
+ std::vector<double> probs = boost::assign::list_of(1.0)(2.0)(1.0)(4.0);
+ boost::random::discrete_distribution<> dist(probs);
+ std::stringstream stream;
+ stream << dist;
+ boost::random::discrete_distribution<> restored_dist;
+ stream >> restored_dist;
+ BOOST_CHECK_EQUAL(dist, restored_dist);
+}
+
+BOOST_AUTO_TEST_CASE(test_generation) {
+ std::vector<double> probs = boost::assign::list_of(0.0)(1.0);
+ boost::minstd_rand0 gen;
+ boost::random::discrete_distribution<> dist;
+ boost::random::discrete_distribution<> dist_r(probs);
+ for(int i = 0; i < 10; ++i) {
+ int value = dist(gen);
+ BOOST_CHECK_EQUAL(value, 0);
+ int value_r = dist_r(gen);
+ BOOST_CHECK_EQUAL(value_r, 1);
+ int value_param = dist_r(gen, dist.param());
+ BOOST_CHECK_EQUAL(value_param, 0);
+ int value_r_param = dist(gen, dist_r.param());
+ BOOST_CHECK_EQUAL(value_r_param, 1);
+ }
+}