def _reciprocal_condition_number(lu_mat, one_norm):
    r"""Compute reciprocal condition number of a matrix.

    Args:
        lu_mat (numpy.ndarray): A 2D array of a matrix :math:`A` that has been
            LU-factored, with the non-diagonal part of :math:`L` stored in the
            strictly lower triangle and :math:`U` stored in the upper triangle.
        one_norm (float): The 1-norm of the original matrix :math:`A`.

    Returns:
        float: The reciprocal condition number of :math:`A`.

    Raises:
        OSError: If SciPy is not installed.
        RuntimeError: If the reciprocal 1-norm condition number could not
            be computed.
    """
    if _scipy_lapack is None:
        raise OSError("This function requires SciPy for calling into LAPACK.")

    # pylint: disable=no-member
    rcond, info = _scipy_lapack.dgecon(lu_mat, one_norm)
    # pylint: enable=no-member
    if info != 0:
        raise RuntimeError(
            "The reciprocal 1-norm condition number could not be computed."
        )

    return rcond
r"""Compute reciprocal condition number of a matrix.

    Args:
        lu_mat (numpy.ndarray): A 2D array of a matrix :math:`A` that has been
            LU-factored, with the non-diagonal part of :math:`L` stored in the
            strictly lower triangle and :math:`U` stored in the upper triangle.
        one_norm (float): The 1-norm of the original matrix :math:`A`.

    Returns:
        float: The reciprocal condition number of :math:`A`.

    Raises:
        OSError: If SciPy is not installed.
        RuntimeError: If the reciprocal 1-norm condition number could not
            be computed.