     
     /**
       The polar representation heading angle of the vector, in radians.
+    
+        let v = C4Vector(1,1,0)
+        v.heading //-> M_PI_4
      */
     public var heading : Double {
         get {


    /**
      The angle between two vectors, based on a provided point
     */
    public func angleTo(vec: C4Vector, basedOn: C4Vector) -> Double {
        var vecA = self


    /**
      Return `true` if the vector is zero.
    
        let v = C4Vector()
        v.isZero() //-> true
     */
    public func isZero() -> Bool {
        return x == 0 && y == 0 && z == 0
