I am going though a functional source that has the following class:

<!-- language: lang-cpp -->

     class Point3D
     {
           int x ,y,z;

           int vSize2() const
           {
               return x*x +
	                  y*y +
	                  z*z;
           }


           int vSize() const
           {
             return sqrt(vSize2());
           }           
     };


It is hard to understand the functionalities of the above two functions (`vSize2()` and `vSize()`). It seems to me that it is calculating the length between the point and the origin. 

Any thoughts?