Evaluates the Bessel function of the first kind of order 1 (J1), based on the implementations of Press et al. (1986).
Press, William H., Brian P. Flannery, Saul A. Teukolsky, and William T. Vetterling. Numerical Recipes - The Art of Scientific Computing. Cambridge University Press (1986): 988 p.
function besselJ1 extends Modelica.Icons.Function; input Real x "Independent variable"; output Real J1 "Bessel function J1(x)"; end besselJ1;