code: def calcRotcurve(Pot,Rs,phi=None):
      
      try:
          grid= len(Rs)
      except TypeError:
          grid=1
          Rs= nu.array([Rs])
      rotcurve= nu.zeros(grid)
      for ii in range(grid):
          rotcurve[ii]= vcirc(Pot,Rs[ii],phi=phi,use_physical=False)
      return rotcurve
docs: NAME:
  
         calcRotcurve
  
      PURPOSE:
  
         calculate the rotation curve for this potential (in the z=0 plane for
         non-spherical potentials)
  
      INPUT:
  
         Pot - Potential or list of Potential instances
  
         Rs - (array of) radius(i)
  
         phi= (None) azimuth to use for non-axisymmetric potentials
  
      OUTPUT:
  
         array of vc
  
      HISTORY:
  
         2011-04-13 - Written - Bovy (NYU)
  
         2016-06-15 - Added phi= keyword for non-axisymmetric potential - Bovy (UofT)