ReduceOrder:

-------------------------------------------------------------------------------
   Retain states k of the system a,b,c,d
-------------------------------------------------------------------------------
   Form:
   g = ReduceOrder( g, k )
-------------------------------------------------------------------------------

   ------
   Inputs
   ------
   g			        (:)    State space system

   -------
   Outputs
   -------
   g			        (:)    State space system

-------------------------------------------------------------------------------

Children:

Common: Classes/@statespace/statespace.m