math/test/test_sinc.cpp

111 lines
4.0 KiB
C++

// (C) Copyright John Maddock 2018.
// 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 <pch_light.hpp>
#include "test_sinc.hpp"
#include <boost/multiprecision/cpp_bin_float.hpp>
#include <boost/math/special_functions/next.hpp>
//
// DESCRIPTION:
// ~~~~~~~~~~~~
//
// This file tests the sinc_pi function. There are two sets of tests, spot
// tests which compare our results with selected values computed
// using the online special function calculator at
// functions.wolfram.com, while the bulk of the accuracy tests
// use values generated with NTL::RR at 1000-bit precision
// and our generic versions of these functions.
//
// Note that when this file is first run on a new platform many of
// these tests will fail: the default accuracy is 1 epsilon which
// is too tight for most platforms. In this situation you will
// need to cast a human eye over the error rates reported and make
// a judgement as to whether they are acceptable. Either way please
// report the results to the Boost mailing list. Acceptable rates of
// error are marked up below as a series of regular expressions that
// identify the compiler/stdlib/platform/data-type/test-data/test-function
// along with the maximum expected peek and RMS mean errors for that
// test.
//
void expected_results()
{
//
// Define the max and mean errors expected for
// various compilers and platforms.
//
add_expected_result(
".*", // compiler
".*", // stdlib
".*", // platform
".*", // test type(s)
".*", // test data group
".*", 3, 3); // test function
//
// Finish off by printing out the compiler/stdlib/platform names,
// we do this to make it easier to mark up expected error rates.
//
std::cout << "Tests run with " << BOOST_COMPILER << ", "
<< BOOST_STDLIB << ", " << BOOST_PLATFORM << std::endl;
}
template <class T>
void test_close_to_transition()
{
T transition = 3.3f * boost::math::tools::forth_root_epsilon<T>();
T val = transition;
for (unsigned i = 0; i < 100; ++i)
{
boost::multiprecision::cpp_bin_float_50 extended = val;
extended = sin(extended) / extended;
T expected = extended.template convert_to<T>();
T result = boost::math::sinc_pi(val);
BOOST_CHECK_LE(boost::math::epsilon_difference(result, expected), 3);
result = boost::math::sinc_pi(-val);
BOOST_CHECK_LE(boost::math::epsilon_difference(result, expected), 3);
val = boost::math::float_prior(val);
}
for (unsigned i = 0; i < 100; ++i)
{
boost::multiprecision::cpp_bin_float_50 extended = val;
extended = sin(extended) / extended;
T expected = extended.template convert_to<T>();
T result = boost::math::sinc_pi(val);
BOOST_CHECK_LE(boost::math::epsilon_difference(result, expected), 3);
result = boost::math::sinc_pi(-val);
BOOST_CHECK_LE(boost::math::epsilon_difference(result, expected), 3);
val = boost::math::float_next(val);
}
}
BOOST_AUTO_TEST_CASE( test_main )
{
BOOST_MATH_CONTROL_FP;
expected_results();
test_sinc(0.1F, "float");
test_close_to_transition<float>();
test_sinc(0.1, "double");
test_close_to_transition<double>();
#ifndef BOOST_MATH_NO_LONG_DOUBLE_MATH_FUNCTIONS
test_sinc(0.1L, "long double");
test_close_to_transition<long double>();
#ifndef BOOST_MATH_NO_REAL_CONCEPT_TESTS
test_sinc(boost::math::concepts::real_concept(0.1), "real_concept");
#endif
#else
std::cout << "<note>The long double tests have been disabled on this platform "
"either because the long double overloads of the usual math functions are "
"not available at all, or because they are too inaccurate for these tests "
"to pass.</note>" << std::endl;
#endif
}