math/test/empirical_cumulative_distribution_test.cpp

70 lines
1.8 KiB
C++

/*
* Copyright Nick Thompson, 2019
* Use, modification and distribution are subject to 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)
*/
#include "math_unit_test.hpp"
#include <numeric>
#include <utility>
#include <random>
#include <boost/core/demangle.hpp>
#include <boost/math/distributions/empirical_cumulative_distribution_function.hpp>
#ifdef BOOST_HAS_FLOAT128
#include <boost/multiprecision/float128.hpp>
using boost::multiprecision::float128;
#endif
using boost::math::empirical_cumulative_distribution_function;
template<class Z>
void test_uniform_z()
{
std::vector<Z> v{6,3,4,1,2,5};
auto ecdf = empirical_cumulative_distribution_function(std::move(v));
CHECK_ULP_CLOSE(1.0/6.0, ecdf(1), 1);
CHECK_ULP_CLOSE(2.0/6.0, ecdf(2), 1);
CHECK_ULP_CLOSE(3.0/6.0, ecdf(3), 1);
CHECK_ULP_CLOSE(4.0/6.0, ecdf(4), 1);
CHECK_ULP_CLOSE(5.0/6.0, ecdf(5), 1);
CHECK_ULP_CLOSE(6.0/6.0, ecdf(6), 1);
// Less trivial:
v = {6,3,4,1,1,1,2,4};
ecdf = empirical_cumulative_distribution_function(std::move(v));
CHECK_ULP_CLOSE(3.0/8.0, ecdf(1), 1);
CHECK_ULP_CLOSE(4.0/8.0, ecdf(2), 1);
CHECK_ULP_CLOSE(5.0/8.0, ecdf(3), 1);
CHECK_ULP_CLOSE(7.0/8.0, ecdf(4), 1);
CHECK_ULP_CLOSE(7.0/8.0, ecdf(5), 1);
CHECK_ULP_CLOSE(8.0/8.0, ecdf(6), 1);
}
template<class Real>
void test_uniform()
{
size_t n = 128;
std::vector<Real> v(n);
for (size_t i = 0; i < n; ++i) {
v[i] = Real(i+1)/Real(n);
}
auto ecdf = empirical_cumulative_distribution_function(std::move(v));
for (size_t i = 0; i < n; ++i) {
CHECK_ULP_CLOSE(Real(i+1)/Real(n), ecdf(Real(i+1)/Real(n)), 1);
}
}
int main()
{
test_uniform_z<int>();
test_uniform<double>();
return boost::math::test::report_errors();
}