code: def calcELAxi(R,vR,vT,pot,vc=1.,ro=1.):
                                 
      return (potentialAxi(R,pot)+vR**2./2.+vT**2./2.,R*vT)
docs: NAME:
         calcELAxi
      PURPOSE:
         calculate the energy and angular momentum
      INPUT:
         R - Galactocentric radius (/ro)
         vR - radial part of the velocity (/vc)
         vT - azimuthal part of the velocity (/vc)
         vc - circular velocity
         ro - reference radius
      OUTPUT:
         (E,L)
      HISTORY:
         2010-11-30 - Written - Bovy (NYU)