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Improve Bessel Y derivative coverage.

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Also fixes a bug in bessel_y_derivative_small_z_series corner case.
This commit is contained in:
jzmaddock
2024-02-06 18:26:35 +00:00
parent e1033c9558
commit 60134c06e9
3 changed files with 21 additions and 2 deletions
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5
include/boost/math/special_functions/detail/bessel_jy_derivatives_series.hpp
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@@ -147,6 +147,7 @@ inline T bessel_y_derivative_small_z_series(T v, T x, const Policy& pol)
T p = log(x / 2);
T scale = 1;
bool need_logs = (v >= boost::math::max_factorial<T>::value) || (boost::math::tools::log_max_value<T>() / v < fabs(p));
if (!need_logs)
{
gam = boost::math::tgamma(v, pol);
@@ -204,7 +205,9 @@ inline T bessel_y_derivative_small_z_series(T v, T x, const Policy& pol)
T b = boost::math::tools::sum_series(s2, boost::math::policies::get_epsilon<T, Policy>(), max_iter);
result += scale * prefix * b;
return result;
if(scale * tools::max_value<T>() < result)
return boost::math::policies::raise_overflow_error<T>(function, nullptr, pol);
return result / scale;
}
// Calculating of BesselY'(v,x) with small x (x < epsilon) and integer x using derivatives

2
test/test_bessel_y_prime.cpp
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@@ -276,7 +276,7 @@ void expected_results()
".*", // platform
largest_type, // test type(s)
".*", // test data group
".*", 700, 300); // test function
".*", 720, 600); // test function
//
// One set of float tests has inexact input values, so there is a slight error:
//

16
test/test_bessel_y_prime.hpp
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@@ -225,5 +225,21 @@ void test_bessel_prime(T, const char* name)
BOOST_CHECK_THROW(boost::math::cyl_neumann_prime(T(2.5), T(-1)), std::domain_error);
BOOST_CHECK_THROW(boost::math::sph_neumann_prime(2, T(0)), std::domain_error);
BOOST_CHECK_THROW(boost::math::sph_neumann_prime(2, T(-1)), std::domain_error);
BOOST_IF_CONSTEXPR(std::numeric_limits<T>::has_infinity && (std::numeric_limits<T>::min_exponent < -1072))
{
static const std::array<std::array<T, 3>, 5> yv_prime_coverage_data = { {
{{ SC_(170.25), SC_(2), SC_(4.1990285871978876642542582761856953686528755802132926772620e306) }},
#if LDBL_MAX_10_EXP > 4936
{{ SC_(14.25), ldexp(T(1), -1072), SC_(1.830622575805420777640505999291582751497710200210963689466e4936)}},
#else
{{ SC_(14.25), ldexp(T(1), -1072), std::numeric_limits<T>::infinity() }},
#endif
{{ SC_(14.25), ldexp(T(1), -1074), std::numeric_limits<T>::infinity() }},
{{ SC_(15.25), ldexp(T(1), -1074), std::numeric_limits<T>::infinity() }},
{{ SC_(30.25), ldexp(T(1), -1045), std::numeric_limits<T>::infinity() }},
} };
do_test_cyl_neumann_y_prime<T>(yv_prime_coverage_data, name, "y': Extra coverage data");
}
}