Map elements from given `order` array to bins of start and end values
        for radius or angle dimension.

def _get_bins(self, kind, order, reverse=False):
        """
        Map elements from given `order` array to bins of start and end values
        for radius or angle dimension.
        """

        if kind == "radius":
            start = self.max_radius * self.radius_inner
            end = self.max_radius

        elif kind == "angle":
            start = self.start_angle
            end = self.start_angle + 2 * np.pi

        bounds = np.linspace(start, end, len(order) + 1)
        bins = np.vstack([bounds[:-1], bounds[1:]]).T

        if reverse:
            bins = bins[::-1]

        return dict(zip(order, bins))