def is_best_response(self, own_action, opponents_actions, tol=None):
        """
        Return True if `own_action` is a best response to
        `opponents_actions`.

        Parameters
        ----------
        own_action : scalar(int) or array_like(float, ndim=1)
            An integer representing a pure action, or an array of floats
            representing a mixed action.

        opponents_actions : see `best_response`

        tol : scalar(float), optional(default=None)
            Tolerance level used in determining best responses. If None,
            default to the value of the `tol` attribute.

        Returns
        -------
        bool
            True if `own_action` is a best response to
            `opponents_actions`; False otherwise.

        """
        if tol is None:
            tol = self.tol

        payoff_vector = self.payoff_vector(opponents_actions)
        payoff_max = payoff_vector.max()

        if isinstance(own_action, numbers.Integral):
            return payoff_vector[own_action] >= payoff_max - tol
        else:
            return np.dot(own_action, payoff_vector) >= payoff_max - tol