update plots in neb explorer slow

[ruehle]

Don't redraw everything but update curves instead could be better?

[js850]

matplotlib is very slow in general. drawing the disconnectivity graph is very slow for large graphs. I imagine there are ways to speed it up. For animations (i.e. updating existing lines), using

line, = axes.plot()

then updating with line.set_ydata() should be much much faster than using plot() over and over again.