Function rgsl::gamma_beta::incomplete_gamma::gamma_inc_P_e

pub fn gamma_inc_P_e(a: f64, x: f64) -> (Value, Result)

This routine computes the complementary normalized incomplete Gamma Function P(a,x) = 1 - Q(a,x) = 1/\Gamma(a) \int_0^x dt t^{a-1} \exp(-t) for a > 0, x >= 0.

Note that Abramowitz & Stegun call P(a,x) the incomplete gamma function (section 6.5).