def __init__(self, band_names=['delta', 'theta', 'alpha', 'beta'],
                 ch_names=['TP9', 'AF7', 'AF8', 'TP10']):
        """
        """
        self.band_names = band_names
        self.ch_names = ch_names
        self.n_bars = self.band_names * self.ch_names

        self.x =

        self.fig, self.ax = plt.subplots()
        self.ax.set_ylim((0, 1))

        y = np.zeros((self.n_bars,))
        x = range(self.n_bars)

        self.rects = self.ax.bar(x, y)