Map elements from given `order` array to bins ranging from `start`
        to `end`.

def _map_order_to_ticks(start, end, order, reverse=False):
        """Map elements from given `order` array to bins ranging from `start`
        to `end`.
        """
        size = len(order)
        bounds = np.linspace(start, end, size + 1)
        if reverse:
            bounds = bounds[::-1]
        mapping = list(zip(bounds[:-1]%(np.pi*2), order))
        return mapping