code: def _computeArray(self, funcTilde, R, z, phi):
          
          R = nu.array(R,dtype=float); z = nu.array(z,dtype=float); phi = nu.array(phi,dtype=float);
          
          shape = (R*z*phi).shape
          if shape == (): return nu.sum(self._compute(funcTilde, R,z,phi))
          R = R*nu.ones(shape); z = z*nu.ones(shape); phi = phi*nu.ones(shape);
          func = nu.zeros(shape, float)
  
          
          li = _cartesian(shape)
          for i in range(li.shape[0]):
              j = nu.split(li[i], li.shape[1])
              func[j] = nu.sum(self._compute(funcTilde, R[j][0],z[j][0],phi[j][0]))
          return func
docs: NAME:
             _computeArray
          PURPOSE:
             evaluate the density or potential for a given array of coordinates
          INPUT:
             funcTidle - must be _rhoTilde or _phiTilde
             R - Cylindrical Galactocentric radius
             z - vertical height
             phi - azimuth
          OUTPUT:
             density or potential evaluated at (R,z, phi)
          HISTORY:
             2016-06-02 - Written - Aladdin