code: def x(self,*args,**kwargs):
          
          thiso= self(*args,**kwargs)
          if not len(thiso.shape) == 2: thiso= thiso.reshape((thiso.shape[0],1))
          if len(thiso[:,0]) == 2:
              return thiso[0,:]
          if len(thiso[:,0]) != 4 and len(thiso[:,0]) != 6:
              raise AttributeError("orbit must track azimuth to use x()")
          elif len(thiso[:,0]) == 4:
              return thiso[0,:]*nu.cos(thiso[3,:])
          else:
              return thiso[0,:]*nu.cos(thiso[5,:])
docs: NAME:
             x
          PURPOSE:
             return x
          INPUT:
             t - (optional) time at which to get x
             ro= (Object-wide default) physical scale for distances to use to convert
             use_physical= use to override Object-wide default for using a physical scale for output
          OUTPUT:
             x(t)
          HISTORY:
             2010-09-21 - Written - Bovy (NYU)