Function rgsl::elliptic::legendre::incomplete::ellint_D

pub fn ellint_D(phi: f64, k: f64, n: f64, mode: Mode) -> f64

This routine computes the incomplete elliptic integral D(\phi,k) which is defined through the Carlson form RD(x,y,z) by the following relation,

D(\phi,k,n) = (1/3)(\sin(\phi))³ RD (1-\sin^2(\phi), 1-k² \sin^2(\phi), 1).

The argument n is not used and will be removed in a future release.