def g_measure(self):
return self.pr_gmean()<EOL>
r"""Return G-measure.

        :math:`G`-measure is the geometric mean of precision and recall:
        :math:`\sqrt{precision \cdot recall}`

        This is identical to the Fowlkes–Mallows (FM) index for two
        clusters.

        Cf. https://en.wikipedia.org/wiki/F1_score#G-measure

        Cf. https://en.wikipedia.org/wiki/Fowlkes%E2%80%93Mallows_index

        Returns
        -------
        float
            The :math:`G`-measure of the confusion table

        Example
        -------
        >>> ct = ConfusionTable(120, 60, 20, 30)
        >>> ct.g_measure()
        0.828078671210825