plot after clearing current plot

def plot(self, x, y, panel='top', xlabel=None, **kws):
        """plot after clearing current plot """
        panel = self.get_panel(panel)
        panel.plot(x, y, **kws)
        if xlabel is not None:
            self.xlabel = xlabel
        if self.xlabel is not None:
            self.panel_bot.set_xlabel(self.xlabel)