Hello!
I started using matblotlib few days ago, and like it.
I encountered the following problem:
I have a figure with two subplots. I use the toolbar for going back and
forth after changing axes’ scales. I want to change something in the
graphs from time to time – like shifting some lines elsewhere
(by editing lines’ properties). By playing with this I found a strange
behaviour of the axes() command:
I thought that calling simple axes(‘existing axes instance’) should
only make the ‘existing axes instance’ current. But, at least for me,
this command also resets the possibility of using back & forward
buttons. Is this really wanted?
What I truly want to achieve is to be able to use those navigation
buttons independently on what is drawn in the axes – only taking care
of the scales. I use the first subplot for visualizing input data, the
second subplot for visualizing fft of the input data. I have two
additional vertical lines in the former plot for selecting the range of
the input data to be then passed to fft. I want to be able to change
scales of both graphs at any time and do not discontinue this ability
by adding new things to the graphs…
- is the described behaviour of axes() function intended?
- what events have some influence on navigation buttons?
- what shall I read in order to be able to exercise some control over the buttons?
Thank you a lot! 
Ruda Sykora