diff options
Diffstat (limited to 'boost/math/special_functions/detail/bessel_ik.hpp')
| -rw-r--r-- | boost/math/special_functions/detail/bessel_ik.hpp | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/boost/math/special_functions/detail/bessel_ik.hpp b/boost/math/special_functions/detail/bessel_ik.hpp index 10118d9715..aac1781e10 100644 --- a/boost/math/special_functions/detail/bessel_ik.hpp +++ b/boost/math/special_functions/detail/bessel_ik.hpp @@ -374,6 +374,7 @@ int bessel_ik(T v, T x, T* I, T* K, int kind, const Policy& pol) prev = Ku; current = Ku1; T scale = 1; + T scale_sign = 1; for (k = 1; k <= n; k++) // forward recurrence for K { T fact = 2 * (u + k) / x; @@ -381,6 +382,7 @@ int bessel_ik(T v, T x, T* I, T* K, int kind, const Policy& pol) { prev /= current; scale /= current; + scale_sign *= boost::math::sign(current); current = 1; } next = fact * current + prev; @@ -426,7 +428,7 @@ int bessel_ik(T v, T x, T* I, T* K, int kind, const Policy& pol) if(fact == 0) *I = Iv; else if(tools::max_value<T>() * scale < fact) - *I = (org_kind & need_i) ? T(sign(fact) * sign(scale) * policies::raise_overflow_error<T>(function, 0, pol)) : T(0); + *I = (org_kind & need_i) ? T(sign(fact) * scale_sign * policies::raise_overflow_error<T>(function, 0, pol)) : T(0); else *I = Iv + fact / scale; // reflection formula } @@ -435,7 +437,7 @@ int bessel_ik(T v, T x, T* I, T* K, int kind, const Policy& pol) *I = Iv; } if(tools::max_value<T>() * scale < Kv) - *K = (org_kind & need_k) ? T(sign(Kv) * sign(scale) * policies::raise_overflow_error<T>(function, 0, pol)) : T(0); + *K = (org_kind & need_k) ? T(sign(Kv) * scale_sign * policies::raise_overflow_error<T>(function, 0, pol)) : T(0); else *K = Kv / scale; BOOST_MATH_INSTRUMENT_VARIABLE(*I); |