[matplotlib-devel] Plots with two scales for the y axis

[Baptiste C. <bap...@al...>]

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