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 ?

Thank you in advance.