def qmean(nums):
return (sum(i ** <NUM_LIT:2> for i in nums) / len(nums)) ** <NUM_LIT:0.5><EOL>
r"""Return quadratic mean.

    The quadratic mean of precision and recall is defined as:
    :math:`\sqrt{\sum\limits_{i} \frac{num_i^2}{|nums|}}`

    Cf. https://en.wikipedia.org/wiki/Quadratic_mean

    Parameters
    ----------
    nums : list
        A series of numbers

    Returns
    -------
    float
        The quadratic mean of nums

    Examples
    --------
    >>> qmean([1, 2, 3, 4])
    2.7386127875258306
    >>> qmean([1, 2])
    1.5811388300841898
    >>> qmean([0, 5, 1000])
    577.3574860228857