This function returns y = atan2(u1, u2, y0), where y is an angle, such that tan(y) = u1/u2 and y is in the range -π rad < y - y0 ≤ π rad. u2 may be zero, provided u1 is not zero.
The difference from atan2() is the optional third argument y0 that specifies which of the infinite many solutions is returned. Note that for the default case (y0 = 0), the result is the same as from atan2().
function atan3 extends Modelica.Math.Icons.AxisCenter; input Real u1 annotation( Dialog(__Dymola_label = "<html><i>u</i><sub>1</sub></html>")); input Real u2 annotation( Dialog(__Dymola_label = "<html><i>u</i><sub>2</sub></html>")); input Q.Angle y0 = 0 "<html><i>y</i> shall be in the range: -π < <i>y</i> - <i>y</i><sub>0</sub> ≤ π</html>" annotation( Dialog(__Dymola_label = "<html><i>y</i><sub>0</sub></html>")); output Q.Angle y annotation( Dialog(__Dymola_label = "<html><i>y</i></html>")); end atan3;