[Matplotlib-users] subclassing AutoDateFormatter correctly

[C M <cmp...@gm...>]

How can I correctly subclass AutoDateFormatter and use it in my code?

What I am doing is copying the code from matplotlib's AutoDateFormatter and
changing the strings for how the dates are represented and making that a
class, MyAutoDateFormatter.  AutoDateFormatter expects a locator, and I
think (?) the default is AutoDateLocator.  So in my code I am doing this:

        adl = AutoDateLocator()
        myformatter = MyAutoDateFormatter(adl)
        axis.xaxis.set_major_formatter(myformatter)

But when I run it, no matter the level of zoom, it says "2010" (when it
should change depending on zoom level).

However, if I go into the matplotlib dates.py code itself and save the same
changes to the date strings there, and I comment out the above code, then it
works:  the date strings change depending on level of zoom.

I could just leave it changed in mpl's dates.py module, but I'd rather
subclass AutoDateFormatter so that if I share the source code of my app with
others, it will get this right.

What am I doing wrong?

Thanks, and any help appreciated as always.

Che