[Matplotlib-users] I need to force the "rounding" of x axis limits

[giacomo b. <gia...@gm...>]

INTRO
=====

please consider the following code (I'm trying to draw a timeline)

1 from matplotlib import pyplot, patches
2 fig = pyplot.figure()
3 ax = fig.add_subplot('111')
4 ax.add_patch(patches.Rectangle((1933,0.25), 73, 0.5))
5 pyplot.show()

that gives me a plot with the x axis that goes from 0.0 to 1.0,
now consider

  ...
5 ax.set_xlim((1933,1933+73))
6 pyplot.show()

this gives me an x axis that goes _exactly_ from 1933 to 2006,
eventually drawing a line superposed to the lower spine

  ...
5 ax.plot((1933,1933+73),(0,0))
6 pyplot.show()

gives me what I really want, that is an x axis running from 1930 to
2010, with the limits automatically rounded by matplotlib...

(I noted that the extra line forces a rounding also for the y axis
limits, but that's not a problem...)

QUESTION
========

I want matplotlib to round the limits of the x axis automatically,
when given explicitly the lower and upper limits of the data, how to?

Thank you in advance

-- 
"We have met the enemy and he is us."
                                                        --- Pogo.