'If *ignore* is *False*, the order of vmin, vmax
does not matter; the original axis orientation will
be preserved. In addition, the view limits can be
expanded, but will not be reduced.  This method is
for mpl internal use; for normal use, see
:meth:`~matplotlib.axes.Axes.set_ylim`.'

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

    if ignore:
        self.axes.viewLim.intervaly = (vmin, vmax)
    else:
        (Vmin, Vmax) = self.get_view_interval()
        if (Vmin < Vmax):
            self.axes.viewLim.intervaly = (min(vmin, vmax, Vmin), max(vmin, vmax, Vmax))
        else:
            self.axes.viewLim.intervaly = (max(vmin, vmax, Vmin), min(vmin, vmax, Vmax))
    self.stale = True
