Re: [Matplotlib-users] Format date tick labels

[Damon M. <dam...@gm...>]

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...

-- 
Damon McDougall
http://www.damon-is-a-geek.com
B2.39
Mathematics Institute
University of Warwick
Coventry
West Midlands
CV4 7AL
United Kingdom