Function authalic_lat_inverse 

pub fn authalic_lat_inverse(beta: f64, apa: &[f64], proj: &Proj, qp: f64) -> f64

Compute the geographic latitude from beta = authalic_latitude where APA = pj_compute_coefficients_for_inverse_authalic_lat() and qp = pj_authalic_lat_q(1, proj.e, proj.one_es)