def basis_transform_vectorU_from_rfmbasis_to_Cartesian(Jac_dUCart_dDrfmUD, src_vectorU):
    Cart_dst_vectorU = ixp.zerorank1()
    for i in range(3):
        for l in range(3):
            Cart_dst_vectorU[i] += (Jac_dUCart_dDrfmUD[i][l] * src_vectorU[l])
    return Cart_dst_vectorU
def basis_transform_vectorU_from_rfmbasis_to_Cartesian(Jac_dUCart_dDrfmUD, src_vectorU):
    Cart_dst_vectorU = ixp.zerorank1()
    for i in range(3):
        for l in range(3):
            Cart_dst_vectorU[i] += (Jac_dUCart_dDrfmUD[i][l] * src_vectorU[l])
    return Cart_dst_vectorU