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gamma.hpp coverage.

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jzmaddock
2024-07-03 19:52:07 +01:00
parent d8a4900e59
commit 24ede6fcdd
3 changed files with 34 additions and 6 deletions
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18
include/boost/math/special_functions/gamma.hpp
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@@ -1436,7 +1436,7 @@ T gamma_incomplete_imp(T a, T x, bool normalised, bool invert,
optimised_invert = true;
}
else
init_value = 0;
init_value = 0; // LCOV_EXCL_LINE Unreachable for any "sensible" floating point type.
}
else
init_value = 0;
@@ -1546,15 +1546,18 @@ T gamma_incomplete_imp(T a, T x, bool normalised, bool invert,
}
if(p_derivative)
{
//
// Need to convert prefix term to derivative:
//
/*
* We can never reach this:
if((x < 1) && (tools::max_value<T>() * x < *p_derivative))
{
// overflow, just return an arbitrarily large value:
*p_derivative = tools::max_value<T>() / 2;
}
*/
BOOST_MATH_ASSERT((x >= 1) || (tools::max_value<T>() * x >= *p_derivative));
//
// Need to convert prefix term to derivative:
//
*p_derivative /= x;
}
@@ -1800,7 +1803,10 @@ T tgamma_ratio_imp(T x, T y, const Policy& pol)
//
// Result will almost certainly overflow, try logs just in case:
//
return exp(boost::math::lgamma(x, pol) - boost::math::lgamma(y, pol));
prefix = boost::math::lgamma(x, pol) - boost::math::lgamma(y, pol);
if (prefix > boost::math::tools::log_max_value<T>())
return policies::raise_overflow_error<T>("tgamma_ratio", nullptr, pol);
return exp(prefix);
}
//
// Regular case, x and y both large and similar in magnitude: