Re: [Matplotlib-users] Format date tick labels

[Benjamin R. <ben...@ou...>]

On Thu, Oct 11, 2012 at 4:53 PM, Mark Lawrence <bre...@ya...>wrote:

> On 11/10/2012 10:55, Damon McDougall wrote:
> > On Wed, Oct 10, 2012 at 5:00 PM, Benjamin Root <ben...@ou...> wrote:
> >>
> >>
> >> On Wed, Oct 10, 2012 at 10:55 AM, Mark Lawrence <
> bre...@ya...>
> >> wrote:
> >>>
> >>> On 10/10/2012 15:41, Mark Lawrence wrote:
> >>>> On 10/10/2012 14:29, Benjamin Root wrote:
> >>>>>
> >>>>> I know of a few people who have difficulties with matplotlib's
> datetime
> >>>>> handling, but they are usually operating on the scale of milliseconds
> >>>>> or
> >>>>> less (lightning data), in which case, one is already at the edge of
> the
> >>>>> resolution handled by python's datetime objects.  However, we would
> >>>>> certainly welcome any sort of examples of how matplotlib fails in
> >>>>> handling
> >>>>> seconds scale and lower plots.
> >>>>>
> >>>>> Cheers!
> >>>>> Ben Root
> >>>>>
> >>>>>
> >>>>
> >>>> I'll assume that the milliseconds above is a typo.  From
> >>>> http://docs.python.org/library/datetime.html "class
> datetime.timedelta A
> >>>> duration expressing the difference between two date, time, or datetime
> >>>> instances to microsecond resolution."  Still, what's a factor of 1000
> >>>> amongst friends? :)
> >>>>
> >>>
> >>> http://www.python.org/dev/peps/pep-0418/ has been implemented in
> Python
> >>> 3.3 and talks about clocks with nanosecond resolutions.  I've flagged
> it
> >>> up here just in case people weren't aware.
> >>>
> >>
> >> Ah, you are right, I meant microseconds.
> >>
> >> With apologies to Spaceballs:
> >>
> >> "Prepare to go to microsecond resolution!"
> >> "No, no, microsecond resolution is too slow"
> >> "Microsecond resolution is too slow?"
> >> "Yes, too slow. We must use nanosecond resolution!"
> >> "Prep-- Prepare Python, for nanosecond resolution!"
> >>
> >> Cheers!
> >> Ben Root
> >
> > Am I missing something here? Are seconds just floats internally? A
> > delta of 1e-6 is nothing (pardon the pun). A delta of 1e-9 is the
> > *least* I'd expect. Maybe even 1e-12. Perhaps the python interpreter
> > doesn't do any denormalising<
> http://stackoverflow.com/questions/9314534/why-does-changing-0-1f-to-0-slow-down-performance-by-10x
> >
> > when encountered with deltas very close to zero...
> >
>
> What percentage of computer users wants a delta of 1e-12?  I suspect
> that the vast majority of users couldn't care two hoots about miniscule
> time deltas in a world where changing time zones can cause chaos.  Where
> some applications cannot handle years before 1970, or 1904, or 1900 or
> whatever.  Or they can't go too far forward, 2036 I think but don't
> quote me.  Where people like myself had to put a huge amount of effort
> into changing code so that applications would carry on working when the
> date flipped over from 31st December 1999 to 1st January 2000.  If
> things were that simple why is matplotlib using third party modules like
> dateutil and pytz?  Why doesn't the "batteries included" Python already
> provide this functionality?
>
>
Preach on, my brother! Preach on!

[psst -- you are facing the choir...]

Cheers!
Ben Root