matplotlib-devel Mailing List for matplotlib

Hello,
here is a proposition of a new strategy for interactive plotting in GTK 
(probably also WX), that doesn't need IPython, and runs the mainloop in 
a separate thread from the calculations.
It has no impact on the user unless he chooses to make use of it, and a 
small impact on the backend developper.
It works in two parts:
matplotlib/__init__.py imports a gtk_protect function that returns a 
wrapper around "dangerous" functions or methods.
The one proposed here (protect_mutex.py) encloses the actual function 
call in a gtk.threads_enter() / gtk.threads_leave() pair in order to 
acquire the GTK mutex.
The same strategy seems possible in WX, though I encountered a lot of 
annoying little problems with WX 2.4. If someone is interested in taking 
over that part, please ask me (I usually don't use WX).
For the non-interactive case, matplotlib defines a dummy gtk_protect 
function which returns its own input, i.e. nothing is changed in that case.
Then all the backend as to do is call gtk_protect on dangerous functions 
or methods in order to replace them with a wrapper. The wrapper has 
little overhead, so I may have protected more than needed.
How to use:
after applying the patch, you have to change your rc params to actually 
use it. Change your .matplotlibrc to contain the following:
backend : GTKAgg # or GTK or GTKCairo
interactive : True
gui_protect : Mutex
Afterwards, you can run most of the examples with python -i, and modify 
the plots to your liking :-)
Cheers,
BC

Hello,
I tried to improve the way of plotting two scales (cf 
examples/two_scales.py). The attached patch contains the following changes:
in axis.py: allow right side label, so both y axes can get one. axis 
instances get a new property: label_position, which is left or right for 
yaxis, top or bottom for xaxis.
in axes.py: a new Axes subclass (TwinAxes) that shares the x axis with 
another. Transforms are set accordingly (lazy values for x lims are 
shared). This avoids having to change the xlim or xlabel (and so on) 2 
times.
in pylab.py: a new command (twin) that returns the twin of an axes 
instance (the current one by default), thus making it into a two scales 
plot.
How to use: see the new examples/two_scales.py for the typical use case.
Cheers,
BC