[Matplotlib-users] But report: Date axis formatter problem

[Jianbao T. <jia...@gm...>]

Problem: The autodatelocator and autodateformatter don't seem to work
properly. One, the formatter doesn't seem to work immediately after being
applied to an axis. A manual call to the locator seems necessary. Two, the
autodatelocator doesn't seem to be able to handle view intervals less than
1 second, i.e., the tick labels don't show digits beyond second. You can
see this by zooming the example figure from the code below to a level
shorter than one second.

1. Operating system: OS X 10.8.2
2. matplotlib version: 1.2.0rc2
3. I installed matplotlib via:

pip install git+https://github.com/matplotlib/matplotlib.git#egg=matplotlib-dev

4. Backend: TkAgg, but I don't think the problem depends on the backend.
5. Code:
#--------------------------------- code
-----------------------------------------------------
# Running in ipython --pylab mode.
fig = figure()
tsta = num2epoch(date2num(datetime.datetime.now()))
tarr = tsta + arange(0, 60*30., 0.01) # half hour, dt = 0.01 sec
x = np.array(num2date(epoch2num(tarr)))
nt = len(tarr)
y = randn(nt)

ax = fig.add_subplot(111)
ax.plot(x, y)
fig.canvas.draw()  # Show an overall view of the data


locator = mpl.dates.AutoDateLocator()
formatter = mpl.dates.AutoDateFormatter(locator)

formatter.scaled = {
    365.0 : '%Y',
    30. : '%b %Y',
    1.0 : '%b %d',
    1./24. : '%H:%M',
    1./24./60. : '%M:%S',
    1./24./60./60. : '%S',
}
ax.get_xaxis().set_major_formatter(formatter)  # Won't work immediately.
locator.set_axis(ax.xaxis) # Have to manually make this call and the one
below.
locator.refresh()               # Another manual call.
fig.canvas.draw()
#------------------------------------ end of code
--------------------------------------------------------