'Creates and displays a plot window, or activates it
(gives it focus) if it has already been created.'

def show(self):

    if (self._window and (not self._window.has_exit)):
        self._window.activate()
    else:
        self._win_args['visible'] = True
        self.axes.reset_resources()
        if hasattr(self, '_doctest_depends_on'):
            self._win_args['runfromdoctester'] = True
        self._window = PlotWindow(self, **self._win_args)
