nfinities or NaNs.

    Returns
    -------
    K : 2-D ndarray with shape (N*N, N*N)
        Kronecker form of the Frechet derivative of the matrix exponential.

    Notes
    -----
    This function is used to help compute the condition number
    of the matrix exponential.

    See Also
    --------
    expm : Compute a matrix exponential.
    expm_frechet : Compute the Frechet derivative of the matrix exponential.
    expm_cond : Compute the relative condition number of the matrix exponential
                in the Frobenius norm.

    r