I'm graphing data from a web service, and seem to have stumbled upon a bug when dates are graphed without any values.
Here's a minimum repro: import datetime import matplotlib.pyplot as plt fig = plt.figure() ax = fig.add_subplot(111) x = [] st = datetime.datetime(2012,11,21) while st < datetime.datetime(2012,11,21, 16, 00): x.append(st) st = st + datetime.timedelta(minutes=30) y = [None] * len(x) ax.plot(x,y) fig.autofmt_xdate() plt.show() The stack trace I get: Traceback (most recent call last): File "min_mpl.py", line 15, in <module> fig.autofmt_xdate() File "c:\python26\lib\site-packages\matplotlib\figure.py", line 318, in autofmt_xdate for label in ax.get_xticklabels(): File "c:\python26\lib\site-packages\matplotlib\axes.py", line 2507, in get_xticklabels self.xaxis.get_ticklabels(minor=minor)) File "c:\python26\lib\site-packages\matplotlib\axis.py", line 1104, in get_ticklabels return self.get_majorticklabels() File "c:\python26\lib\site-packages\matplotlib\axis.py", line 1088, in get_majorticklabels ticks = self.get_major_ticks() File "c:\python26\lib\site-packages\matplotlib\axis.py", line 1186, in get_major_ticks numticks = len(self.get_major_locator()()) File "c:\python26\lib\site-packages\matplotlib\dates.py", line 749, in __call__ self.refresh() File "c:\python26\lib\site-packages\matplotlib\dates.py", line 758, in refresh dmin, dmax = self.viewlim_to_dt() File "c:\python26\lib\site-packages\matplotlib\dates.py", line 530, in viewlim_to_dt return num2date(vmin, self.tz), num2date(vmax, self.tz) File "c:\python26\lib\site-packages\matplotlib\dates.py", line 289, in num2date if not cbook.iterable(x): return _from_ordinalf(x, tz) File "c:\python26\lib\site-packages\matplotlib\dates.py", line 203, in _from_ordinalf dt = datetime.datetime.fromordinal(ix) ValueError: ordinal must be >= 1 Adding a 0 & the current date stops getting the exception, but the range seems wildly messed up. (2011 - 2014). ------------------------------------------------------------------------------ Monitor your physical, virtual and cloud infrastructure from a single web console. Get in-depth insight into apps, servers, databases, vmware, SAP, cloud infrastructure, etc. Download 30-day Free Trial. Pricing starts from $795 for 25 servers or applications! http://p.sf.net/sfu/zoho_dev2dev_nov _______________________________________________ Matplotlib-users mailing list Matplotlib-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-users