Angle calculator from sin and cos values

This function uniquely determines the angle (-180,180] in degree or（-pi, pi] in radian

This function uniquely determines the angle (-180,180] in degree or（-pi, pi] in radian from sine and cosine values.

Usage:
theta=angleCalc(S,C,out_mode)

S: sin value of the angle
C: cos value of the angle
out_mode: 'deg' OR 'rad'
the default output mode is in degree

Example:
theta= angleCalc(sin(-2*pi/3),cos(-2*pi/3))
theta = -120;
theta= angleCalc(sin(2*pi/3),cos(2*pi/3),'rad')
theta= 2.0944 [rad]