Control Points of a Random NURBS based-Geometry

Hi all respected members,

I am learning the Isogeometric Analysis technique (which was firstly outlined by Hughes et al.). I am not able to understand the pre-defined control point data of given geometries, therefore I want to know the way in which the information of control points (for the geometries construced by NURBS) can be extracted if we have the geometry. If it is calculated by available software or by any other mean please let me know.

Thanks