Function statrs::function::gamma::checked_gamma_lr [−][src]
pub fn checked_gamma_lr(a: f64, x: f64) -> Result<f64>
Computes the lower incomplete regularized gamma function
P(a,x) = 1 / Gamma(a) * int(exp(-t)t^(a-1), t=0..x) for real a > 0, x > 0
where a is the argument for the gamma function and x is the upper
integral limit.
Remarks
Returns f64::NAN if either argument is f64::NAN
Errors
if a or x are not in (0, +inf)