I am new to matplotlib and I am trying to use it in a python script that make some calculations. I have a method "draw" which take as arguments some values that I want to plot. The method ends with a plt.show(). The first time "draw" is called everything is fine. I see very nice curves. I shut the window openned by matplotlib and some other calculations are performed. But the second time I call "draw" I don't see anything. What should I do to make it work ?