This function returns y = tan(u), with -∞ < u < ∞ (if u is a multiple of (2n-1)*pi/2, y = tan(u) is +/- infinity).
function tan extends Modelica.Math.Icons.AxisCenter; input Modelica.Units.SI.Angle u "Independent variable"; output Real y "Dependent variable y=tan(u)"; end tan;