Thread: [Matplotlib-users] Where are AutoDateLocator and AutoDateFormatter?

Hey folks,

IN old mailing list messages, I see reference to:

mpl.ticker.AutoDateLocator
mpl.ticker.AutoDateFormatter


Where might I find these now? They don't seem to be in matplotlib.ticker 
or matplotlib.date. do they have a new name? Is there a new way to get 
automatic date tic location and formating?

note: I'm trying to do this for the x axis of a quiver plot, which 
doesn't seem to support passing in dates directly.

Thanks,

-Chris




-- 
Christopher Barker, Ph.D.
Oceanographer

Emergency Response Division
NOAA/NOS/OR&R            (206) 526-6959   voice
7600 Sand Point Way NE   (206) 526-6329   fax
Seattle, WA  98115       (206) 526-6317   main reception

Chr...@no...

Hi Chris,

On Fri, May 15, 2009 at 21:29, Christopher Barker <Chr...@no...> wrote:
> Hey folks,
>
> IN old mailing list messages, I see reference to:
>
> mpl.ticker.AutoDateLocator
> mpl.ticker.AutoDateFormatter
>
>
> Where might I find these now? They don't seem to be in matplotlib.ticker
> or matplotlib.date. do they have a new name? Is there a new way to get
> automatic date tic location and formating?

In [14]: from matplotlib import dates

In [15]: dates.Au
dates.AutoDateFormatter  dates.AutoDateLocator

> note: I'm trying to do this for the x axis of a quiver plot, which
> doesn't seem to support passing in dates directly.

simple snippet (with some additional formatting and stuff you might need):

In [13]: dateFmt = mpl.dates.DateFormatter('%Y-%m-%d')

In [14]: ax2.xaxis.set_major_formatter(dateFmt)

In [15]: daysLoc = mpl.dates.DayLocator()

In [16]: hoursLoc = mpl.dates.HourLocator(interval=6)

In [17]: ax2.xaxis.set_major_locator(daysLoc)

In [18]: ax2.xaxis.set_minor_locator(hoursLoc)

In [19]: fig.autofmt_xdate(bottom=0.18) # adjust for correct date labels display

In [20]: fig.subplots_adjust(left=0.18)


HTH

Cheers,
-- 
Sandro Tosi (aka morph, morpheus, matrixhasu)
My website: http://matrixhasu.altervista.org/
Me at Debian: http://wiki.debian.org/SandroTosi

Sandro Tosi wrote:
>> mpl.ticker.AutoDateLocator
>> mpl.ticker.AutoDateFormatter
>>
>> Where might I find these now? They don't seem to be in matplotlib.ticker
>> or matplotlib.date. do they have a new name? Is there a new way to get
>> automatic date tic location and formating?

> dates.AutoDateFormatter  dates.AutoDateLocator

thanks -- I did just find it myself, by looking at the code in 
axes.plot_dates -- however, the plot_dates docstring is wrong, and they 
don't seem to be here:

http://matplotlib.sourceforge.net/api/dates_api.html

They are there in the diagram on top, but don't seem to be on the page.


>> note: I'm trying to do this for the x axis of a quiver plot, which
>> doesn't seem to support passing in dates directly.

by the way, is that a bug that should be tracked down and fixed?

> simple snippet (with some additional formatting and stuff you might need):

thanks. In this case, I'm writing plotting code that I want to work with 
time series that may span hours, or days, or weeks, or months, ...

hence by desire for Auto Formatting.

It does work, but not all that well, though:

> In [19]: fig.autofmt_xdate(bottom=0.18) # adjust for correct date labels display

Thanks, this one helps a lot.0


However, in this case, I'm trying to write method that takes an axes 
object, and plots to that -- how can I do this without the figure reference?

But it does work well if you apply it to the figure after my plotting 
routines.

see enclosed for what I'm doing -- this is for plotting wind data and 
the like, where you have a time series of speeds and directions.

-Chris




-- 
Christopher Barker, Ph.D.
Oceanographer

Emergency Response Division
NOAA/NOS/OR&R            (206) 526-6959   voice
7600 Sand Point Way NE   (206) 526-6329   fax
Seattle, WA  98115       (206) 526-6317   main reception

Chr...@no...

On Fri, May 15, 2009 at 4:23 PM, Christopher Barker
<Chr...@no...> wrote:
> Sandro Tosi wrote:
>>>
>>> mpl.ticker.AutoDateLocator
>>> mpl.ticker.AutoDateFormatter
>>>
>>> Where might I find these now? They don't seem to be in matplotlib.ticker
>>> or matplotlib.date. do they have a new name? Is there a new way to get
>>> automatic date tic location and formating?
>
>> dates.AutoDateFormatter  dates.AutoDateLocator
>
> thanks -- I did just find it myself, by looking at the code in
> axes.plot_dates -- however, the plot_dates docstring is wrong, and they
> don't seem to be here:

I updated the plot_dates docstring in svn to point to matplotlib.dates

> http://matplotlib.sourceforge.net/api/dates_api.html
>
> They are there in the diagram on top, but don't seem to be on the page.

That is odd -- any sphinx gurus have any idea why these are not being
picked up by the automodule code?

>>> note: I'm trying to do this for the x axis of a quiver plot, which
>>> doesn't seem to support passing in dates directly.
>
> by the way, is that a bug that should be tracked down and fixed?

Not all of the methods currently support direct date/unit plotting,
but we do try to extend support when we have reported failures, so if
you post a script which exposes the problem I'll try and fix it.

> However, in this case, I'm trying to write method that takes an axes object,
> and plots to that -- how can I do this without the figure reference?

Most mpl objects have a reference to their parent, so you can walk up
the containment hierarchy, eg

  line.axes.figure.canvas

so in your case

  ax.figure.autofmt_xdate()

but note that autofmt_xdate is designed to work for subplots with only
one column, not in the case of general axes configurations, so calling
this from an axes in a method that does not know how the axes are
layed out does not make sense.  But you can do the main part yourself

  for label in ax.get_xticklabels():
      label.set_rotation(30)
      label.set_horizontalalignment('right')

> But it does work well if you apply it to the figure after my plotting
> routines.

That is the best place to apply it, because there you know the subplot
layout is suitable for the call.

JDH

John Hunter wrote:
> <Chr...@no...> wrote:
> I updated the plot_dates docstring in svn to point to matplotlib.dates

great, thanks!

> Not all of the methods currently support direct date/unit plotting,
> but we do try to extend support when we have reported failures, so if
> you post a script which exposes the problem I'll try and fix it.

OK. Enclosed. If you uncomment the "date2num" call, it works fine, but 
it crashes as it is.

Thanks,
-Chris



-- 
Christopher Barker, Ph.D.
Oceanographer

Emergency Response Division
NOAA/NOS/OR&R            (206) 526-6959   voice
7600 Sand Point Way NE   (206) 526-6329   fax
Seattle, WA  98115       (206) 526-6317   main reception

Chr...@no...