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- // Copyright Paul A. Bristow 2006, 2017.
- // Copyright John Maddock 2006.
- // 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)
- // test_students_t.cpp
- // http://en.wikipedia.org/wiki/Student%27s_t_distribution
- // http://www.itl.nist.gov/div898/handbook/eda/section3/eda3664.htm
- // Basic sanity test for Student's t probability (quantile) (0. < p < 1).
- // and Student's t probability Quantile (0. < p < 1).
- #ifdef _MSC_VER
- # pragma warning (disable :4127) // conditional expression is constant.
- #endif
- #define BOOST_TEST_MAIN
- #include <boost/test/unit_test.hpp> // Boost.Test
- #include <boost/test/tools/floating_point_comparison.hpp>
- #include <boost/math/concepts/real_concept.hpp> // for real_concept
- #include <boost/math/tools/test.hpp> // for real_concept
- #include "test_out_of_range.hpp"
- #include <boost/math/distributions/students_t.hpp>
- using boost::math::students_t_distribution;
- #include <iostream>
- using std::cout;
- using std::endl;
- using std::setprecision;
- #include <limits>
- using std::numeric_limits;
- template <class RealType>
- RealType naive_pdf(RealType v, RealType t)
- {
- // Calculate the pdf of the students t in a deliberately
- // naive way, using equation (5) from
- // http://mathworld.wolfram.com/Studentst-Distribution.html
- // This is equivalent to, but a different method
- // to the one in the actual implementation, so can be used as
- // a very basic sanity check. However some published values
- // would be nice....
- using namespace std; // for ADL
- using boost::math::beta;
- //return pow(v / (v + t*t), (1+v) / 2) / (sqrt(v) * beta(v/2, RealType(0.5f)));
- RealType result = boost::math::tgamma_ratio((v+1)/2, v/2);
- result /= sqrt(v * boost::math::constants::pi<RealType>());
- result /= pow(1 + t*t/v, (v+1)/2);
- return result;
- }
- template <class RealType>
- void test_spots(RealType)
- {
- // Basic sanity checks
- RealType tolerance = static_cast<RealType>(1e-4); // 1e-6 (as %)
- // Some tests only pass at 1e-5 because probability value is less accurate,
- // a digit in 6th decimal place, although calculated using
- // a t-distribution generator (claimed 6 decimal digits) at
- // http://faculty.vassar.edu/lowry/VassarStats.html
- // http://faculty.vassar.edu/lowry/tsamp.html
- // df = 5, +/-t = 2.0, 1-tailed = 0.050970, 2-tailed = 0.101939
- cout << "Tolerance for type " << typeid(RealType).name() << " is " << tolerance << " %" << endl;
- // http://en.wikipedia.org/wiki/Student%27s_t_distribution#Table_of_selected_values
- // Using tabulated value of t = 3.182 for 0.975, 3 df, one-sided.
- // http://www.mth.kcl.ac.uk/~shaww/web_page/papers/Tdistribution06.pdf refers to:
- // A lookup table of quantiles of the RealType distribution
- // for 1 to 25 in steps of 0.1 is provided in CSV form at:
- // www.mth.kcl.ac.uk/~shaww/web_page/papers/Tsupp/tquantiles.csv
- // gives accurate t of -3.1824463052837 and 3 degrees of freedom.
- // Values below are from this source, saved as tquantiles.xls.
- // DF are across the columns, probabilities down the rows
- // and the t- values (quantiles) are shown.
- // These values are probably accurate to nearly 64-bit double
- // (perhaps 14 decimal digits).
- BOOST_CHECK_CLOSE(
- ::boost::math::cdf(
- students_t_distribution<RealType>(2), // degrees_of_freedom
- static_cast<RealType>(-6.96455673428326)), // t
- static_cast<RealType>(0.01), // probability.
- tolerance); // %
- BOOST_CHECK_CLOSE(
- ::boost::math::cdf(
- students_t_distribution<RealType>(5), // degrees_of_freedom
- static_cast<RealType>(-3.36492999890721)), // t
- static_cast<RealType>(0.01), // probability.
- tolerance);
- BOOST_CHECK_CLOSE(
- ::boost::math::cdf(
- students_t_distribution<RealType>(1), // degrees_of_freedom
- static_cast<RealType>(-31830.988607907)), // t
- static_cast<RealType>(0.00001), // probability.
- tolerance);
- BOOST_CHECK_CLOSE(
- ::boost::math::cdf(
- students_t_distribution<RealType>(25.), // degrees_of_freedom
- static_cast<RealType>(-5.2410429995425)), // t
- static_cast<RealType>(0.00001), // probability.
- tolerance);
- BOOST_CHECK_CLOSE(
- ::boost::math::cdf(
- students_t_distribution<RealType>(1), // degrees_of_freedom
- static_cast<RealType>(-63661.97723)), // t
- static_cast<RealType>(0.000005), // probability.
- tolerance);
- BOOST_CHECK_CLOSE(
- ::boost::math::cdf(
- students_t_distribution<RealType>(5.), // degrees_of_freedom
- static_cast<RealType>(-17.89686614)), // t
- static_cast<RealType>(0.000005), // probability.
- tolerance);
- BOOST_CHECK_CLOSE(
- ::boost::math::cdf(
- students_t_distribution<RealType>(25.), // degrees_of_freedom
- static_cast<RealType>(-5.510848412)), // t
- static_cast<RealType>(0.000005), // probability.
- tolerance);
- BOOST_CHECK_CLOSE(
- ::boost::math::cdf(
- students_t_distribution<RealType>(10.), // degrees_of_freedom
- static_cast<RealType>(-1.812461123)), // t
- static_cast<RealType>(0.05), // probability.
- tolerance);
- BOOST_CHECK_CLOSE(
- ::boost::math::cdf(
- students_t_distribution<RealType>(10), // degrees_of_freedom
- static_cast<RealType>(1.812461123)), // t
- static_cast<RealType>(0.95), // probability.
- tolerance);
- BOOST_CHECK_CLOSE(
- ::boost::math::cdf(
- complement(
- students_t_distribution<RealType>(10), // degrees_of_freedom
- static_cast<RealType>(1.812461123))), // t
- static_cast<RealType>(0.05), // probability.
- tolerance);
- BOOST_CHECK_CLOSE(
- ::boost::math::cdf(
- students_t_distribution<RealType>(10), // degrees_of_freedom
- static_cast<RealType>(9.751995491)), // t
- static_cast<RealType>(0.999999), // probability.
- tolerance);
- BOOST_CHECK_CLOSE(
- ::boost::math::cdf(
- students_t_distribution<RealType>(10.), // degrees_of_freedom - for ALL degrees_of_freedom!
- static_cast<RealType>(0.)), // t
- static_cast<RealType>(0.5), // probability.
- tolerance);
- // Student's t Inverse function tests.
- // Special cases
- BOOST_MATH_CHECK_THROW(boost::math::quantile(
- students_t_distribution<RealType>(1.), // degrees_of_freedom (ignored).
- static_cast<RealType>(0)), std::overflow_error); // t == -infinity.
- BOOST_MATH_CHECK_THROW(boost::math::quantile(
- students_t_distribution<RealType>(1.), // degrees_of_freedom (ignored).
- static_cast<RealType>(1)), std::overflow_error); // t == +infinity.
- BOOST_CHECK_EQUAL(boost::math::quantile(
- students_t_distribution<RealType>(1.), // degrees_of_freedom (ignored).
- static_cast<RealType>(0.5)), // probability == half - special case.
- static_cast<RealType>(0)); // t == zero.
- BOOST_CHECK_EQUAL(boost::math::quantile(
- complement(
- students_t_distribution<RealType>(1.), // degrees_of_freedom (ignored).
- static_cast<RealType>(0.5))), // probability == half - special case.
- static_cast<RealType>(0)); // t == zero.
- BOOST_CHECK_CLOSE(boost::math::quantile(
- students_t_distribution<RealType>(1.), // degrees_of_freedom (ignored).
- static_cast<RealType>(0.5)), // probability == half - special case.
- static_cast<RealType>(0), // t == zero.
- tolerance);
- BOOST_CHECK_CLOSE( // Tests of p middling.
- ::boost::math::cdf(
- students_t_distribution<RealType>(5.), // degrees_of_freedom
- static_cast<RealType>(-0.559429644)), // t
- static_cast<RealType>(0.3), // probability.
- tolerance);
- BOOST_CHECK_CLOSE(
- ::boost::math::quantile(
- students_t_distribution<RealType>(5.), // degrees_of_freedom
- static_cast<RealType>(0.3)), // probability.
- static_cast<RealType>(-0.559429644), // t
- tolerance);
- BOOST_CHECK_CLOSE(
- ::boost::math::quantile(
- complement(
- students_t_distribution<RealType>(5.), // degrees_of_freedom
- static_cast<RealType>(0.7))), // probability.
- static_cast<RealType>(-0.559429644), // t
- tolerance);
- BOOST_CHECK_CLOSE( // Tests of p high.
- ::boost::math::cdf(
- students_t_distribution<RealType>(5.), // degrees_of_freedom
- static_cast<RealType>(1.475884049)), // t
- static_cast<RealType>(0.9), // probability.
- tolerance);
- BOOST_CHECK_CLOSE(
- ::boost::math::quantile(
- students_t_distribution<RealType>(5.), // degrees_of_freedom
- static_cast<RealType>(0.9)), // probability.
- static_cast<RealType>(1.475884049), // t
- tolerance);
- BOOST_CHECK_CLOSE( // Tests of p low.
- ::boost::math::cdf(
- students_t_distribution<RealType>(5.), // degrees_of_freedom
- static_cast<RealType>(-1.475884049)), // t
- static_cast<RealType>(0.1), // probability.
- tolerance);
- BOOST_CHECK_CLOSE(
- ::boost::math::quantile(
- students_t_distribution<RealType>(5.), // degrees_of_freedom
- static_cast<RealType>(0.1)), // probability.
- static_cast<RealType>(-1.475884049), // t
- tolerance);
- BOOST_CHECK_CLOSE(
- ::boost::math::cdf(
- students_t_distribution<RealType>(2.), // degrees_of_freedom
- static_cast<RealType>(-6.96455673428326)), // t
- static_cast<RealType>(0.01), // probability.
- tolerance);
- BOOST_CHECK_CLOSE(
- ::boost::math::quantile(
- students_t_distribution<RealType>(2.), // degrees_of_freedom
- static_cast<RealType>(0.01)), // probability.
- static_cast<RealType>(-6.96455673428326), // t
- tolerance);
- //
- // Some special tests to exercise the double-precision approximations
- // to the quantile:
- //
- // tolerance is 50 eps expressed as a persent:
- //
- tolerance = boost::math::tools::epsilon<RealType>() * 5000;
- BOOST_CHECK_CLOSE(boost::math::quantile(
- students_t_distribution<RealType>(2.00390625L), // degrees_of_freedom.
- static_cast<RealType>(0.5625L)), // probability.
- static_cast<RealType>(0.178133131573788108465134803511798566L), // t.
- tolerance);
- BOOST_CHECK_CLOSE(boost::math::quantile(
- students_t_distribution<RealType>(1L), // degrees_of_freedom.
- static_cast<RealType>(0.03125L)), // probability.
- static_cast<RealType>(-10.1531703876088604621071476634194722L), // t.
- tolerance);
- BOOST_CHECK_CLOSE(boost::math::quantile(
- students_t_distribution<RealType>(1L), // degrees_of_freedom.
- static_cast<RealType>(0.875L)), // probability.
- static_cast<RealType>(2.41421356237309504880168872421390942L), // t.
- tolerance);
- BOOST_CHECK_CLOSE(boost::math::quantile(
- students_t_distribution<RealType>(2L), // degrees_of_freedom.
- static_cast<RealType>(0.03125L)), // probability.
- static_cast<RealType>(-3.81000381000571500952501666878143315L), // t.
- tolerance);
- BOOST_CHECK_CLOSE(boost::math::quantile(
- students_t_distribution<RealType>(2L), // degrees_of_freedom.
- static_cast<RealType>(0.875L)), // probability.
- static_cast<RealType>(1.60356745147454630810732088527854144L), // t.
- tolerance);
- BOOST_CHECK_CLOSE(boost::math::quantile(
- students_t_distribution<RealType>(4L), // degrees_of_freedom.
- static_cast<RealType>(0.03125L)), // probability.
- static_cast<RealType>(-2.56208431914409044861223047927635034L), // t.
- tolerance);
- BOOST_CHECK_CLOSE(boost::math::quantile(
- students_t_distribution<RealType>(4L), // degrees_of_freedom.
- static_cast<RealType>(0.875L)), // probability.
- static_cast<RealType>(1.34439755550909142430681981315923574L), // t.
- tolerance);
- BOOST_CHECK_CLOSE(boost::math::quantile(
- students_t_distribution<RealType>(6L), // degrees_of_freedom.
- static_cast<RealType>(0.03125L)), // probability.
- static_cast<RealType>(-2.28348667906973065861212495010082952L), // t.
- tolerance);
- BOOST_CHECK_CLOSE(boost::math::quantile(
- students_t_distribution<RealType>(6L), // degrees_of_freedom.
- static_cast<RealType>(0.875L)), // probability.
- static_cast<RealType>(1.27334930914664286821103236660071906L), // t.
- tolerance);
- BOOST_CHECK_CLOSE(boost::math::quantile(
- students_t_distribution<RealType>(8L), // degrees_of_freedom.
- static_cast<RealType>(0.03125L)), // probability.
- static_cast<RealType>(-2.16296475406014719458642055768894376L), // t.
- tolerance);
- BOOST_CHECK_CLOSE(boost::math::quantile(
- students_t_distribution<RealType>(8L), // degrees_of_freedom.
- static_cast<RealType>(0.875L)), // probability.
- static_cast<RealType>(1.24031826078267310637634677726479038L), // t.
- tolerance);
- BOOST_CHECK_CLOSE(boost::math::quantile(
- students_t_distribution<RealType>(10L), // degrees_of_freedom.
- static_cast<RealType>(0.03125L)), // probability.
- static_cast<RealType>(-2.09596136475109350926340169211429572L), // t.
- tolerance);
- BOOST_CHECK_CLOSE(boost::math::quantile(
- students_t_distribution<RealType>(10L), // degrees_of_freedom.
- static_cast<RealType>(0.875L)), // probability.
- static_cast<RealType>(1.2212553950039221407185188573696834L), // t.
- tolerance);
- BOOST_CHECK_CLOSE(boost::math::quantile(
- students_t_distribution<RealType>(2.125L), // degrees_of_freedom.
- static_cast<RealType>(0.03125L)), // probability.
- static_cast<RealType>(-3.62246031671091980110493455859296532L), // t.
- tolerance);
- BOOST_CHECK_CLOSE(boost::math::quantile(
- students_t_distribution<RealType>(2.125L), // degrees_of_freedom.
- static_cast<RealType>(0.875L)), // probability.
- static_cast<RealType>(1.56905270993307293450392958697861969L), // t.
- tolerance);
- BOOST_CHECK_CLOSE(boost::math::quantile(
- students_t_distribution<RealType>(3L), // degrees_of_freedom.
- static_cast<RealType>(0.03125L)), // probability.
- static_cast<RealType>(-2.90004411882995814036141778367917946L), // t.
- tolerance);
- BOOST_CHECK_CLOSE(boost::math::quantile(
- students_t_distribution<RealType>(3L), // degrees_of_freedom.
- static_cast<RealType>(0.875L)), // probability.
- static_cast<RealType>(1.42262528146180931868169289781115099L), // t.
- tolerance);
- if(boost::is_floating_point<RealType>::value)
- {
- BOOST_CHECK_CLOSE(boost::math::cdf(
- students_t_distribution<RealType>(1e30f),
- boost::math::quantile(
- students_t_distribution<RealType>(1e30f), static_cast<RealType>(0.25f))),
- static_cast<RealType>(0.25f), tolerance);
- BOOST_CHECK_CLOSE(boost::math::cdf(
- students_t_distribution<RealType>(1e20f),
- boost::math::quantile(
- students_t_distribution<RealType>(1e20f), static_cast<RealType>(0.25f))),
- static_cast<RealType>(0.25f), tolerance);
- BOOST_CHECK_CLOSE(boost::math::cdf(
- students_t_distribution<RealType>(static_cast<RealType>(0x7FFFFFFF)),
- boost::math::quantile(
- students_t_distribution<RealType>(static_cast<RealType>(0x7FFFFFFF)), static_cast<RealType>(0.25f))),
- static_cast<RealType>(0.25f), tolerance);
- BOOST_CHECK_CLOSE(boost::math::cdf(
- students_t_distribution<RealType>(static_cast<RealType>(0x10000000)),
- boost::math::quantile(
- students_t_distribution<RealType>(static_cast<RealType>(0x10000000)), static_cast<RealType>(0.25f))),
- static_cast<RealType>(0.25f), tolerance);
- BOOST_CHECK_CLOSE(boost::math::cdf(
- students_t_distribution<RealType>(static_cast<RealType>(0x0fffffff)),
- boost::math::quantile(
- students_t_distribution<RealType>(static_cast<RealType>(0x0fffffff)), static_cast<RealType>(0.25f))),
- static_cast<RealType>(0.25f), tolerance);
- }
- // Student's t pdf tests.
- // for PDF checks, use 100 eps tolerance expressed as a percent:
- tolerance = boost::math::tools::epsilon<RealType>() * 10000;
- for(unsigned i = 1; i < 20; i += 3)
- {
- for(RealType r = -10; r < 10; r += 0.125)
- {
- //std::cout << "df=" << i << " t=" << r << std::endl;
- BOOST_CHECK_CLOSE(
- boost::math::pdf(
- students_t_distribution<RealType>(static_cast<RealType>(i)),
- r),
- naive_pdf<RealType>(static_cast<RealType>(i), r),
- tolerance);
- }
- }
- RealType tol2 = boost::math::tools::epsilon<RealType>() * 5;
- students_t_distribution<RealType> dist(8);
- RealType x = static_cast<RealType>(0.125);
- using namespace std; // ADL of std names.
- // mean:
- BOOST_CHECK_CLOSE(
- mean(dist)
- , static_cast<RealType>(0), tol2);
- // variance:
- // BOOST_CHECK_CLOSE(
- // variance(dist)
- // , static_cast<RealType>(13.0L / 6.0L), tol2);
- //// was , static_cast<RealType>(8.0L / 6.0L), tol2);
- // std deviation:
- BOOST_CHECK_CLOSE(
- standard_deviation(dist)
- , static_cast<RealType>(sqrt(8.0L / 6.0L)), tol2);
- // hazard:
- BOOST_CHECK_CLOSE(
- hazard(dist, x)
- , pdf(dist, x) / cdf(complement(dist, x)), tol2);
- // cumulative hazard:
- BOOST_CHECK_CLOSE(
- chf(dist, x)
- , -log(cdf(complement(dist, x))), tol2);
- // coefficient_of_variation:
- BOOST_MATH_CHECK_THROW(
- coefficient_of_variation(dist),
- std::overflow_error);
- // mode:
- BOOST_CHECK_CLOSE(
- mean(dist)
- , static_cast<RealType>(0), tol2);
- // median:
- BOOST_CHECK_CLOSE(
- median(dist)
- , static_cast<RealType>(0), tol2);
- // skewness:
- BOOST_CHECK_CLOSE(
- skewness(dist)
- , static_cast<RealType>(0), tol2);
- // kurtosis:
- BOOST_CHECK_CLOSE(
- kurtosis(dist)
- , static_cast<RealType>(4.5), tol2);
- // kurtosis excess:
- BOOST_CHECK_CLOSE(
- kurtosis_excess(dist)
- , static_cast<RealType>(1.5), tol2);
- // Parameter estimation. These results are close to but
- // not identical to those reported on the NIST website at
- // http://www.itl.nist.gov/div898/handbook/prc/section2/prc222.htm
- // the NIST results appear to be calculated using a normal
- // approximation, which slightly under-estimates the degrees of
- // freedom required, particularly when the result is small.
- //
- BOOST_CHECK_EQUAL(
- ceil(students_t_distribution<RealType>::find_degrees_of_freedom(
- static_cast<RealType>(0.5),
- static_cast<RealType>(0.005),
- static_cast<RealType>(0.01),
- static_cast<RealType>(1.0))),
- 99);
- BOOST_CHECK_EQUAL(
- ceil(students_t_distribution<RealType>::find_degrees_of_freedom(
- static_cast<RealType>(1.5),
- static_cast<RealType>(0.005),
- static_cast<RealType>(0.01),
- static_cast<RealType>(1.0))),
- 14);
- BOOST_CHECK_EQUAL(
- ceil(students_t_distribution<RealType>::find_degrees_of_freedom(
- static_cast<RealType>(0.5),
- static_cast<RealType>(0.025),
- static_cast<RealType>(0.01),
- static_cast<RealType>(1.0))),
- 76);
- BOOST_CHECK_EQUAL(
- ceil(students_t_distribution<RealType>::find_degrees_of_freedom(
- static_cast<RealType>(1.5),
- static_cast<RealType>(0.025),
- static_cast<RealType>(0.01),
- static_cast<RealType>(1.0))),
- 11);
- BOOST_CHECK_EQUAL(
- ceil(students_t_distribution<RealType>::find_degrees_of_freedom(
- static_cast<RealType>(0.5),
- static_cast<RealType>(0.05),
- static_cast<RealType>(0.01),
- static_cast<RealType>(1.0))),
- 65);
- BOOST_CHECK_EQUAL(
- ceil(students_t_distribution<RealType>::find_degrees_of_freedom(
- static_cast<RealType>(1.5),
- static_cast<RealType>(0.05),
- static_cast<RealType>(0.01),
- static_cast<RealType>(1.0))),
- 9);
- // Test for large degrees of freedom when should be same as normal.
- RealType inf = std::numeric_limits<RealType>::infinity();
- RealType nan = std::numeric_limits<RealType>::quiet_NaN();
- std::string type = typeid(RealType).name();
- // if (type != "class boost::math::concepts::real_concept") fails for gcc
- if (typeid(RealType) != typeid(boost::math::concepts::real_concept))
- { // Ordinary floats only.
- RealType limit = 1/ boost::math::tools::epsilon<RealType>();
- // Default policy to get full accuracy.
- // std::cout << "Switch over to normal if df > " << limit << std::endl;
- // float Switch over to normal if df > 8.38861e+006
- // double Switch over to normal if df > 4.5036e+015
- // Can't test real_concept - doesn't converge.
- boost::math::normal_distribution<RealType> n(0, 1); //
- students_t_distribution<RealType> st(boost::math::tools::max_value<RealType>()); // Well over the switchover point,
- // PDF
- BOOST_CHECK_EQUAL(pdf(st, 0), pdf(n, 0.)); // Should be exactly equal.
- students_t_distribution<RealType> st2(limit /5 ); // Just below the switchover point,
- BOOST_CHECK_CLOSE_FRACTION(pdf(st2, 0), pdf(n, 0.), tolerance); // Should be very close to normal.
- // CDF
- BOOST_CHECK_EQUAL(cdf(st, 0), cdf(n, 0.)); // Should be exactly equal.
- BOOST_CHECK_CLOSE_FRACTION(cdf(st2, 0), cdf(n, 0.), tolerance); // Should be very close to normal.
- // Tests for df = infinity.
- students_t_distribution<RealType> infdf(inf);
- BOOST_CHECK_EQUAL(infdf.degrees_of_freedom(), inf);
- BOOST_CHECK_EQUAL(mean(infdf), 0); // OK.
- #ifndef BOOST_NO_EXCEPTIONS
- BOOST_MATH_CHECK_THROW(students_t_distribution<RealType> minfdf(-inf), std::domain_error);
- BOOST_MATH_CHECK_THROW(students_t_distribution<RealType> minfdf(nan), std::domain_error);
- BOOST_MATH_CHECK_THROW(students_t_distribution<RealType> minfdf(-nan), std::domain_error);
- #endif
- BOOST_CHECK_EQUAL(pdf(infdf, -inf), 0);
- BOOST_CHECK_EQUAL(pdf(infdf, +inf), 0);
- BOOST_CHECK_EQUAL(cdf(infdf, -inf), 0);
- BOOST_CHECK_EQUAL(cdf(infdf, +inf), 1);
- // BOOST_CHECK_CLOSE_FRACTION(pdf(infdf, 0), static_cast<RealType>(0.3989422804014326779399460599343818684759L), tolerance);
- BOOST_CHECK_CLOSE_FRACTION(pdf(infdf, 0),boost::math::constants::one_div_root_two_pi<RealType>() , tolerance);
- BOOST_CHECK_CLOSE_FRACTION(cdf(infdf, 0),boost::math::constants::half<RealType>() , tolerance);
- // Checks added for Trac #7717 report by Thomas Mang.
- BOOST_MATH_CHECK_THROW(quantile(dist, -1), std::domain_error);
- BOOST_MATH_CHECK_THROW(quantile(dist, 2), std::domain_error);
- BOOST_MATH_CHECK_THROW(pdf(students_t_distribution<RealType>(0), 0), std::domain_error);
- BOOST_MATH_CHECK_THROW(pdf(students_t_distribution<RealType>(-1), 0), std::domain_error);
-
- // Check on df for mean (moment k = 1)
- BOOST_MATH_CHECK_THROW(mean(students_t_distribution<RealType>(nan)), std::domain_error);
- // BOOST_MATH_CHECK_THROW(mean(students_t_distribution<RealType>(inf)), std::domain_error); inf is now OK
- BOOST_MATH_CHECK_THROW(mean(students_t_distribution<RealType>(-1)), std::domain_error);
- BOOST_MATH_CHECK_THROW(mean(students_t_distribution<RealType>(0)), std::domain_error);
- BOOST_MATH_CHECK_THROW(mean(students_t_distribution<RealType>(1)), std::domain_error); // df == k
- BOOST_CHECK_EQUAL(mean(students_t_distribution<RealType>(2)), 0); // OK.
- BOOST_CHECK_EQUAL(mean(students_t_distribution<RealType>(inf)), 0); // OK.
- // Check on df for variance (moment 2)
- BOOST_MATH_CHECK_THROW(variance(students_t_distribution<RealType>(nan)), std::domain_error);
- // BOOST_MATH_CHECK_THROW(variance(students_t_distribution<RealType>(inf)), std::domain_error); // inf is now OK.
- BOOST_MATH_CHECK_THROW(variance(students_t_distribution<RealType>(-1)), std::domain_error);
- BOOST_MATH_CHECK_THROW(variance(students_t_distribution<RealType>(0)), std::domain_error);
- BOOST_MATH_CHECK_THROW(variance(students_t_distribution<RealType>(1)), std::domain_error);
- BOOST_MATH_CHECK_THROW(variance(students_t_distribution<RealType>(static_cast<RealType>(1.99999L))), std::domain_error);
- BOOST_MATH_CHECK_THROW(variance(students_t_distribution<RealType>(static_cast<RealType>(1.99999L))), std::domain_error);
- BOOST_MATH_CHECK_THROW(variance(students_t_distribution<RealType>(2)), std::domain_error); // df ==
- BOOST_CHECK_EQUAL(variance(students_t_distribution<RealType>(2.5)), 5); // OK.
- BOOST_CHECK_EQUAL(variance(students_t_distribution<RealType>(3)), 3); // OK.
- BOOST_CHECK_EQUAL(variance(students_t_distribution<RealType>(inf)), 1); // OK.
- // Check on df for skewness (moment 3)
- BOOST_MATH_CHECK_THROW(skewness(students_t_distribution<RealType>(nan)), std::domain_error);
- BOOST_MATH_CHECK_THROW(skewness(students_t_distribution<RealType>(-1)), std::domain_error);
- BOOST_MATH_CHECK_THROW(skewness(students_t_distribution<RealType>(0)), std::domain_error);
- BOOST_MATH_CHECK_THROW(skewness(students_t_distribution<RealType>(1)), std::domain_error);
- BOOST_MATH_CHECK_THROW(skewness(students_t_distribution<RealType>(1.5L)), std::domain_error);
- BOOST_MATH_CHECK_THROW(skewness(students_t_distribution<RealType>(2)), std::domain_error);
- BOOST_MATH_CHECK_THROW(skewness(students_t_distribution<RealType>(3)), std::domain_error); // df == k
- BOOST_CHECK_EQUAL(skewness(students_t_distribution<RealType>(3.5)), 0); // OK.
- BOOST_CHECK_EQUAL(skewness(students_t_distribution<RealType>(4)), 0); // OK.
- BOOST_CHECK_EQUAL(skewness(students_t_distribution<RealType>(inf)), 0); // OK.
- // Check on df for kurtosis_excess (moment 4)
- BOOST_MATH_CHECK_THROW(kurtosis_excess(students_t_distribution<RealType>(nan)), std::domain_error);
- BOOST_MATH_CHECK_THROW(kurtosis_excess(students_t_distribution<RealType>(-1)), std::domain_error);
- BOOST_MATH_CHECK_THROW(kurtosis_excess(students_t_distribution<RealType>(0)), std::domain_error);
- BOOST_MATH_CHECK_THROW(kurtosis_excess(students_t_distribution<RealType>(1)), std::domain_error);
- BOOST_MATH_CHECK_THROW(kurtosis_excess(students_t_distribution<RealType>(1.5L)), std::domain_error);
- BOOST_MATH_CHECK_THROW(kurtosis_excess(students_t_distribution<RealType>(2)), std::domain_error);
- BOOST_MATH_CHECK_THROW(kurtosis(students_t_distribution<RealType>(static_cast<RealType>(2.1))), std::domain_error);
- BOOST_MATH_CHECK_THROW(kurtosis_excess(students_t_distribution<RealType>(3)), std::domain_error);
- BOOST_MATH_CHECK_THROW(kurtosis_excess(students_t_distribution<RealType>(4)), std::domain_error); // df == k
- BOOST_CHECK_EQUAL(kurtosis_excess(students_t_distribution<RealType>(5)), 6); // OK.
- BOOST_CHECK_EQUAL(kurtosis_excess(students_t_distribution<RealType>(inf)), 0); // OK.
- // Check on df for kurtosis (moment 4)
- BOOST_MATH_CHECK_THROW(kurtosis(students_t_distribution<RealType>(nan)), std::domain_error);
- BOOST_MATH_CHECK_THROW(kurtosis(students_t_distribution<RealType>(-1)), std::domain_error);
- BOOST_MATH_CHECK_THROW(kurtosis(students_t_distribution<RealType>(0)), std::domain_error);
- BOOST_MATH_CHECK_THROW(kurtosis(students_t_distribution<RealType>(1)), std::domain_error);
- BOOST_MATH_CHECK_THROW(kurtosis(students_t_distribution<RealType>(2)), std::domain_error);
- BOOST_MATH_CHECK_THROW(kurtosis(students_t_distribution<RealType>(static_cast<RealType>(2.0001L))), std::domain_error);
- BOOST_MATH_CHECK_THROW(kurtosis(students_t_distribution<RealType>(3)), std::domain_error);
- BOOST_MATH_CHECK_THROW(kurtosis(students_t_distribution<RealType>(4)), std::domain_error); // df == k
- BOOST_CHECK_EQUAL(kurtosis(students_t_distribution<RealType>(5)), 9); // OK.
- BOOST_CHECK_EQUAL(kurtosis(students_t_distribution<RealType>(inf)), 3); // OK.
- }
- // Use a new distribution ignore_error_students_t with a custom policy to ignore all errors,
- // and check returned values are as expected.
- /*
- Sandia-darwin-intel-12.0 - math - test_students_t / intel-darwin-12.0
- ../libs/math/test/test_students_t.cpp(544): error: "domain_error" has already been declared in the current scope
- using boost::math::policies::domain_error;
- ../libs/math/test/test_students_t.cpp(552): error: "pole_error" has already been declared in the current scope
- using boost::math::policies::pole_error;
- Unclear where previous declaration is.
- Does not seem to be in student_t.hpp or any included files???
- So to avoid this perceived problem by this compiler,
- the ignore policy below uses fully specified names.
- */
- using boost::math::policies::policy;
- // Types of error whose action can be altered by policies:.
- //using boost::math::policies::evaluation_error;
- //using boost::math::policies::domain_error;
- //using boost::math::policies::overflow_error;
- //using boost::math::policies::underflow_error;
- //using boost::math::policies::domain_error;
- //using boost::math::policies::pole_error;
- //// Actions on error (in enum error_policy_type):
- //using boost::math::policies::errno_on_error;
- //using boost::math::policies::ignore_error;
- //using boost::math::policies::throw_on_error;
- //using boost::math::policies::denorm_error;
- //using boost::math::policies::pole_error;
- //using boost::math::policies::user_error;
- typedef policy<
- boost::math::policies::domain_error<boost::math::policies::ignore_error>,
- boost::math::policies::overflow_error<boost::math::policies::ignore_error>,
- boost::math::policies::underflow_error<boost::math::policies::ignore_error>,
- boost::math::policies::denorm_error<boost::math::policies::ignore_error>,
- boost::math::policies::pole_error<boost::math::policies::ignore_error>,
- boost::math::policies::evaluation_error<boost::math::policies::ignore_error>
- > my_ignore_policy;
- typedef students_t_distribution<RealType, my_ignore_policy> ignore_error_students_t;
- // Only test NaN and infinity if type has these features (realconcept returns zero).
- // Integers are always converted to RealType,
- // others requires static cast to RealType from long double.
- if(std::numeric_limits<RealType>::has_quiet_NaN)
- {
- // Mean
- BOOST_CHECK((boost::math::isnan)(mean(ignore_error_students_t(-1))));
- BOOST_CHECK((boost::math::isnan)(mean(ignore_error_students_t(0))));
- BOOST_CHECK((boost::math::isnan)(mean(ignore_error_students_t(1))));
- // Variance
- BOOST_CHECK((boost::math::isnan)(variance(ignore_error_students_t(std::numeric_limits<RealType>::quiet_NaN()))));
- BOOST_CHECK((boost::math::isnan)(variance(ignore_error_students_t(-1))));
- BOOST_CHECK((boost::math::isnan)(variance(ignore_error_students_t(0))));
- BOOST_CHECK((boost::math::isnan)(variance(ignore_error_students_t(1))));
- BOOST_CHECK((boost::math::isnan)(variance(ignore_error_students_t(static_cast<RealType>(1.7L)))));
- BOOST_CHECK((boost::math::isnan)(variance(ignore_error_students_t(2))));
- // Skewness
- BOOST_CHECK((boost::math::isnan)(skewness(ignore_error_students_t(std::numeric_limits<RealType>::quiet_NaN()))));
- BOOST_CHECK((boost::math::isnan)(skewness(ignore_error_students_t(-1))));
- BOOST_CHECK((boost::math::isnan)(skewness(ignore_error_students_t(0))));
- BOOST_CHECK((boost::math::isnan)(skewness(ignore_error_students_t(1))));
- BOOST_CHECK((boost::math::isnan)(skewness(ignore_error_students_t(2))));
- BOOST_CHECK((boost::math::isnan)(skewness(ignore_error_students_t(3))));
- // Kurtosis
- BOOST_CHECK((boost::math::isnan)(kurtosis(ignore_error_students_t(std::numeric_limits<RealType>::quiet_NaN()))));
- BOOST_CHECK((boost::math::isnan)(kurtosis(ignore_error_students_t(-1))));
- BOOST_CHECK((boost::math::isnan)(kurtosis(ignore_error_students_t(0))));
- BOOST_CHECK((boost::math::isnan)(kurtosis(ignore_error_students_t(1))));
- BOOST_CHECK((boost::math::isnan)(kurtosis(ignore_error_students_t(2))));
- BOOST_CHECK((boost::math::isnan)(kurtosis(ignore_error_students_t(static_cast<RealType>(2.0001L)))));
- BOOST_CHECK((boost::math::isnan)(kurtosis(ignore_error_students_t(3))));
- BOOST_CHECK((boost::math::isnan)(kurtosis(ignore_error_students_t(4))));
-
- // Kurtosis excess
- BOOST_CHECK((boost::math::isnan)(kurtosis_excess(ignore_error_students_t(std::numeric_limits<RealType>::quiet_NaN()))));
- BOOST_CHECK((boost::math::isnan)(kurtosis_excess(ignore_error_students_t(-1))));
- BOOST_CHECK((boost::math::isnan)(kurtosis_excess(ignore_error_students_t(0))));
- BOOST_CHECK((boost::math::isnan)(kurtosis_excess(ignore_error_students_t(1))));
- BOOST_CHECK((boost::math::isnan)(kurtosis_excess(ignore_error_students_t(2))));
- BOOST_CHECK((boost::math::isnan)(kurtosis_excess(ignore_error_students_t(static_cast<RealType>(2.0001L)))));
- BOOST_CHECK((boost::math::isnan)(kurtosis_excess(ignore_error_students_t(3))));
- BOOST_CHECK((boost::math::isnan)(kurtosis_excess(ignore_error_students_t(4))));
- } // has_quiet_NaN
- BOOST_CHECK(boost::math::isfinite(mean(ignore_error_students_t(1 + std::numeric_limits<RealType>::epsilon()))));
- BOOST_CHECK(boost::math::isfinite(variance(ignore_error_students_t(2 + 2 * std::numeric_limits<RealType>::epsilon()))));
- BOOST_CHECK(boost::math::isfinite(variance(ignore_error_students_t(static_cast<RealType>(2.0001L)))));
- BOOST_CHECK(boost::math::isfinite(variance(ignore_error_students_t(2 + 2 * std::numeric_limits<RealType>::epsilon()))));
- BOOST_CHECK(boost::math::isfinite(skewness(ignore_error_students_t(3 + 3 * std::numeric_limits<RealType>::epsilon()))));
- BOOST_CHECK(boost::math::isfinite(kurtosis(ignore_error_students_t(4 + 4 * std::numeric_limits<RealType>::epsilon()))));
- BOOST_CHECK(boost::math::isfinite(kurtosis(ignore_error_students_t(static_cast<RealType>(4.0001L)))));
- // check_out_of_range<students_t_distribution<RealType> >(1);
- // Cannot be used because fails "exception std::domain_error is expected but not raised"
- // if df = +infinity is allowed, must use new version that allows skipping infinity tests.
- // Infinite == true
- check_support<students_t_distribution<RealType> >(students_t_distribution<RealType>(1), true);
- } // template <class RealType>void test_spots(RealType)
- BOOST_AUTO_TEST_CASE( test_main )
- {
- // Check that can construct students_t distribution using the two convenience methods:
- using namespace boost::math;
- students_t myst1(2); // Using typedef
- students_t_distribution<> myst2(2); // Using default RealType double.
- //students_t_distribution<double> myst3(2); // Using explicit RealType double.
- // Basic sanity-check spot values.
- // (Parameter value, arbitrarily zero, only communicates the floating point type).
- test_spots(0.0F); // Test float. OK at decdigits = 0 tolerance = 0.0001 %
- test_spots(0.0); // Test double. OK at decdigits 7, tolerance = 1e07 %
- #ifndef BOOST_MATH_NO_LONG_DOUBLE_MATH_FUNCTIONS
- test_spots(0.0L); // Test long double.
- #if !BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT(0x582))
- test_spots(boost::math::concepts::real_concept(0.)); // Test 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
-
- } // BOOST_AUTO_TEST_CASE( test_main )
- /*
- Autorun "i:\boost-06-05-03-1300\libs\math\test\Math_test\debug\test_students_t.exe"
- Running 1 test case...
- Tolerance for type float is 0.0001 %
- Tolerance for type double is 0.0001 %
- Tolerance for type long double is 0.0001 %
- Tolerance for type class boost::math::concepts::real_concept is 0.0001 %
- *** No errors detected
- */
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