gamma
-
constexpr Complex gamma(const Complex &z) noexcept
Evaluates the gamma function [1] for a complex input. Uses the Lanczos approximation [2].
Parameters
- const Complex &z
A complex number.
Returns
- type Complex
A complex number.
The gamma function is an extrapolation of the factorial to complex and decimal inputs. It is defined as follows:
\[\Gamma(z) = \int_{0}^{\infty} t^{z - 1}e^{-t}dt\]
Example
Complex z = 1.0 + 1_j;
std::cout << gamma(z) << "\n";
Output:
0.498016 - 0.15495j
References