def compute_Jacobian_and_inverseJacobian_tofrom_Cartesian():
    Jac_dUCart_dDrfmUD = ixp.zerorank2()
    for i in range(3):
        for j in range(3):
            Jac_dUCart_dDrfmUD[i][j] = sp.diff(xx_to_Cart[i], xx[j])
    (Jac_dUrfm_dDCartUD, dummyDET) = ixp.generic_matrix_inverter3x3(Jac_dUCart_dDrfmUD)
    return (Jac_dUCart_dDrfmUD, Jac_dUrfm_dDCartUD)
def compute_Jacobian_and_inverseJacobian_tofrom_Cartesian():
    Jac_dUCart_dDrfmUD = ixp.zerorank2()
    for i in range(3):
        for j in range(3):
            Jac_dUCart_dDrfmUD[i][j] = sp.diff(xx_to_Cart[i], xx[j])
    (Jac_dUrfm_dDCartUD, dummyDET) = ixp.generic_matrix_inverter3x3(Jac_dUCart_dDrfmUD)
    return (Jac_dUCart_dDrfmUD, Jac_dUrfm_dDCartUD)