function atand( x ) {
	var rad = atan( x );
	return rad2deg( rad );
}
Computes the arctangent (in degrees) of a double-precision floating-point number.

@param {number} x - input value
@returns {number} arctangent (in degrees)

@example
var v = atand( 0.0 );
// returns 0.0

@example
var v = atand( 0.5 );
// returns ~26.57

@example
var v = atand( 1.0 / Math.sqrt( 3.0 ) );
// returns ~30.0

@example
var v = atand( 1.0 );
// returns 45.0

@example
var v = atand( Infinity );
// returns 90.0

@example
var v = atand( NaN );
// returns NaN