def basis_transform_vectorU_from_Cartesian_to_rfmbasis(Jac_dUrfm_dDCartUD, Cart_src_vectorU):
    rfm_dst_vectorU = ixp.zerorank1()
    for i in range(3):
        for l in range(3):
            rfm_dst_vectorU[i] += (Jac_dUrfm_dDCartUD[i][l] * Cart_src_vectorU[l])
    return rfm_dst_vectorU
def basis_transform_vectorU_from_Cartesian_to_rfmbasis(Jac_dUrfm_dDCartUD, Cart_src_vectorU):
    rfm_dst_vectorU = ixp.zerorank1()
    for i in range(3):
        for l in range(3):
            rfm_dst_vectorU[i] += (Jac_dUrfm_dDCartUD[i][l] * Cart_src_vectorU[l])
    return rfm_dst_vectorU