compute/test/test_normal_distribution.cpp

85 lines
2.9 KiB
C++

//---------------------------------------------------------------------------//
// Copyright (c) 2013-2014 Kyle Lutz <kyle.r.lutz@gmail.com>
//
// 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://boostorg.github.com/compute for more information.
//---------------------------------------------------------------------------//
#define BOOST_TEST_MODULE TestNormalDistribution
#include <boost/test/unit_test.hpp>
#include <boost/compute/system.hpp>
#include <boost/compute/command_queue.hpp>
#include <boost/compute/algorithm/count_if.hpp>
#include <boost/compute/container/vector.hpp>
#include <boost/compute/random/default_random_engine.hpp>
#include <boost/compute/random/normal_distribution.hpp>
#include <boost/compute/lambda.hpp>
#include <boost/accumulators/accumulators.hpp>
#include <boost/accumulators/statistics/mean.hpp>
#include <boost/accumulators/statistics/stats.hpp>
#include <boost/accumulators/statistics/variance.hpp>
#include "context_setup.hpp"
template<class Stats, class T>
boost::accumulators::accumulator_set<T, Stats>
accumulate_statistics(const boost::compute::vector<T>& vector,
boost::compute::command_queue& queue) {
// copy vector to the host
std::vector<T> host_vector(vector.size());
boost::compute::copy(
vector.begin(), vector.end(), host_vector.begin(), queue
);
// compute desired statistics and return accumulator object
return std::for_each(
host_vector.begin(),
host_vector.end(),
boost::accumulators::accumulator_set<T, Stats>()
);
}
BOOST_AUTO_TEST_CASE(normal_distribution_doctest)
{
using boost::compute::lambda::_1;
boost::compute::vector<float> vec(10, context);
//! [generate]
// initialize the default random engine
boost::compute::default_random_engine engine(queue);
// setup the normal distribution to produce floats centered at 5
boost::compute::normal_distribution<float> distribution(5.0f, 1.0f);
// generate the random values and store them to 'vec'
distribution.generate(vec.begin(), vec.end(), engine, queue);
//! [generate]
}
BOOST_AUTO_TEST_CASE(normal_distribution_statistics)
{
// generate normally distributed random numbers
const size_t n = 10000;
boost::compute::vector<float> vec(n, context);
boost::compute::default_random_engine engine(queue);
boost::compute::normal_distribution<float> distribution(10.0f, 2.0f);
distribution.generate(vec.begin(), vec.end(), engine, queue);
// compute mean and standard deviation
using namespace boost::accumulators;
accumulator_set<float, stats<tag::variance> > acc =
accumulate_statistics<stats<tag::variance> >(vec, queue);
// check mean and standard deviation are what we expect
BOOST_CHECK_CLOSE(mean(acc), 10.f, 0.5f);
BOOST_CHECK_CLOSE(std::sqrt(variance(acc)), 2.f, 0.5f);
}
BOOST_AUTO_TEST_SUITE_END()