Matplotlib: How to set number of ticks on an axis?

[Caleb Hattingh]

Hi

I tried several Google searches to no avail.  I read through pretty
much most of the online docs at the matplotlib sourceforge site, but
didn't find what I was looking for.  I went through the axis.py and
ticker.py code today, trying to find out how to set the number of
points (ticks) on an axis in Matplotlib.

I know that something like

>>> xticks(arange(5))

will make the x-axis have the values specified, but Matplotlib appears
to have a very nice way of setting axis ticks with human-friendly
values that round in just the right way for a given set of data.  I
still want that functionality, but I want to set how many ticks are on
a given axis.

It seems that the locater() classes are where I should look, and there
seem to be some defaults in ticker.py:

class AutoLocator(MaxNLocator):
    def __init__(self):
        MaxNLocator.__init__(self, nbins=9, steps=[1, 2, 5, 10])

I don't understand what this means :)

I would prefer not to hack this directly in the matplotlib code.   How
can I change the number of ticks on an axis programmatically without
messing with the other ticklabel functionality?   

Caleb