Function one_compartment_cl 

pub fn one_compartment_cl(
    x: &NalgebraVec<f64>,
    p: &NalgebraVec<f64>,
    t: f64,
    rateiv: &NalgebraVec<f64>,
    cov: &Covariates,
) -> NalgebraVec<f64>

Analytical solution for one compartment model parameterized by clearance.

Converts CL/V to ke and delegates to one_compartment.

Assumptions

• p is a vector of length 2 with CL and V in that order
• rateiv is a vector of length 1 with the value of the infusion rate (only one drug)
• x is a vector of length 1
• covariates are not used