code: def ccmodmd_ystep():
      
  
      mAXU = np.mean(mp_D_X + mp_D_U0, axis=0)
      mp_D_Y0[:] = mp_dprox(mAXU)
      AXU1 = mp_DX - mp_S + mp_D_U1
      mp_D_Y1[:] = mp_drho*AXU1 / (mp_W**2 + mp_drho)
docs: Do the Y step of the ccmod stage. There are no parameters
      or return values because all inputs and outputs are from and to
      global variables.