gammq

double gammq(double a, double x);

Returns the incomplete gamma function Qx(a) = 1 - Px(a).

Parameters:
ascalar that specifies the parametric exponent of the integrand
xupper limit of integration

Returns:
Qx(a)

Errors:
NUMERICS_ERROR is raised if x < 0 or a ≤ 0

Header:
#include "mathx.h"