'set the axis data limits'

def set_data_interval(self, vmin, vmax, ignore=False):

    if ignore:
        self.axes.dataLim.intervalx = (vmin, vmax)
    else:
        (Vmin, Vmax) = self.get_data_interval()
        self.axes.dataLim.intervalx = (min(vmin, Vmin), max(vmax, Vmax))
    self.stale = True
