def pr_heronian_mean(self):
return heronian_mean((self.precision(), self.recall()))<EOL>
r"""Return Heronian mean of precision & recall.

        The Heronian mean of precision and recall is defined as:
        :math:`\frac{precision + \sqrt{precision \cdot recall} + recall}{3}`

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

        Returns
        -------
        float
            The Heronian mean of the confusion table's precision & recall

        Example
        -------
        >>> ct = ConfusionTable(120, 60, 20, 30)
        >>> ct.pr_heronian_mean()
        0.8284071761178939