On Tue, Jul 21, 2009 at 8:00 PM, Nick Seow<nicks...@gmail.com> wrote: > Hi, > > I'm worried that I'm doing something stupid, but can't quite spot it. > > testBarCharts() :- X axis in integers. Works fine. > testBarChartsDTMonths() :- X axis in datetimes, 1 month between data > points. Works fine > testBarChartsDTHours() :- X axis in datetimes, 1 hour between data
under the hood, mpl converts datetime objects to days since 1/1/0000, using a floating point representation for fractions of a day. So a bar width or 1.0 corresponds to 1 day. The default width to the bar command is 0.8, which is too thin for months, just right for days, and too wide for hours. Eg, for hours do bar(x, y, width=0.8*1/24.) # width is 0.8 hours for months, do something like bar(x, y, width=0.8*30/24.) # width approx 80% of a month Perhaps bar should take a width=None arg and try to infer the ideal with, eg assuming even spacing, but for now you need to specify the width in fractional days when making bar plots with datetimes. JDH ------------------------------------------------------------------------------ _______________________________________________ Matplotlib-users mailing list Matplotlib-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-users
