25 if (x <= 0.0)
return 0.0;
37 if (std::fabs(del) < std::fabs(sum)*3.0e-7)
38 return sum*std::exp(-x +
a_*std::log(x) - gln);
56 return 1.0-h*std::exp(-x +
a_*std::log(x) - gln);
70 QL_REQUIRE(x>0.0,
"positive argument required");
72 temp -= (x + 0.5)*std::log(temp);
73 Real ser=1.000000000190015;
81 return -temp+std::log(2.5066282746310005*ser/x);
91 return value(x+1.0)/x;
Real operator()(Real x) const
Real logValue(Real x) const
#define QL_REQUIRE(condition, message)
throw an error if the given pre-condition is not verified
#define QL_FAIL(message)
throw an error (possibly with file and line information)
ext::function< Real(Real)> b
std::size_t Size
size of a container