def update_line(self, trace, xdata, ydata, side='left', draw=False,
                    update_limits=True):
        """ update a single trace, for faster redraw """

        x = self.conf.get_mpl_line(trace)
        x.set_data(xdata, ydata)
        datarange = [xdata.min(), xdata.max(), ydata.min(), ydata.max()]
        self.conf.set_trace_datarange(datarange, trace=trace)
        axes = self.axes
        if side == 'right':
            axes = self.get_right_axes()

        if update_limits:
            self.set_viewlimits()
        if draw:
            self.draw()