title: how do I update the x limits in a matplotlib figure in tkinter
body: <p>I made a GUI with TKinter that reads a scope trace from a agilent scope. I want the x axis to update when I change time/div.  To update the x and y data I use <code>set_xdata</code> and <code>set_ydata</code>.  Is there a similar method for updating the x limits?</p>