def install_bower(self, package, save=True, save_dev=False):
        """Installs a bower package.

        :param save: if `True`, pins the package to the Hydrogen requirements
            YAML file.
        :param save_dev: if `True`, pins the package as a development
            dependency to the Hydrogen requirements YAML file.
        :param return: a list of tuples, containing all installed package names
            and versions, including any dependencies.
        """
        requirement = Requirement.coerce(package)
        url = Bower.get_package_url(requirement.package)

        installed = []
        for name, _ in self.get_bower_package(url):
            installed.append(Requirement(name, requirement.version))

        for requirement in installed:
            if save:
                self.requirements["bower"].add(requirement, replace=True)
            if save_dev:
                self.requirements["bower-dev"].add(requirement, replace=True)
            success("installed {}".format(str(requirement)))
        if save or save_dev:
            self.requirements.save()
        return installed
def gerrity_score(self):
        """
        Gerrity Score, which weights each cell in the contingency table by its observed relative frequency.
        :return:
        """
        k = self.table.shape[0]
        n = float(self.table.sum())
        p_o = self.table.sum(axis=0) / n
        p_sum = np.cumsum(p_o)[:-1]
        a = (1.0 - p_sum) / p_sum
        s = np.zeros(self.table.shape, dtype=float)
        for (i, j) in np.ndindex(*s.shape):
            if i == j:
                s[i, j] = 1.0 / (k - 1.0) * (np.sum(1.0 / a[0:j]) + np.sum(a[j:k - 1]))
            elif i < j:
                s[i, j] = 1.0 / (k - 1.0) * (np.sum(1.0 / a[0:i]) - (j - i) + np.sum(a[j:k - 1]))
            else:
                s[i, j] = s[j, i]
        return np.sum(self.table / float(self.table.sum()) * s)