[IPython-dev] [Matplotlib-users] IPython's matplotlib inline magic is really magic? Actually it might resets axes bounds...

Ryan Nelson rnelsonchem at gmail.com
Fri Mar 13 19:00:40 EDT 2015

Thanks Tom.

Your hint led me to the following page:
So it seems that this change is quite old, and I never noticed it before...
The suggestion on that page requires some incantation of the %config magic.
I tried this:
%config InlineBackend.print_figure_kwargs.bbox_inches = None
Which silently passes, but doesn't change the behavior.

Your rational for IPython's use of this kwarg by default is sound, and I
understand that there are valid use cases for it in some circumstances.
However, I still think this is problematic. I like MPL because you can make
a plot to your exact specifications -- but setting this kind of behavior by
default (without a well documented fix) feels a little "Microsoft
Office"-y... That being said, I really don't care all that much. IPython is
a fantastic tool. I'll just move my plotting code to a separate script and
tweak things there. (But then I won't be able to share the notebook with my
fancy plot embedded except as an external image. Can't have everything.)

I actually don't want any sort of 'tight' layout; however, just for
reference, the `tight_layout` function throws an error in my example.


On Fri, Mar 13, 2015 at 4:03 PM, Thomas Caswell <tcaswell at gmail.com> wrote:

> This is due to the fact that by default the inline backend saves the pngs
> using `boundingbox_inches='tight'`.  The design goal on the mpl side of
> this kwargs was to trim off extra whitespace, but the way it is implemented
> works just as effectively to expand to fit artists that fall outside of the
> figure.  I assume the choice to make this the default in inline was to
> waste as little space as possible.
> A possibly more reliable method to get the same effect is to use
> `tight_layout` (see http://matplotlib.org/users/tight_layout_guide.html)
> There was talk of replacing that implementation with a linear constraint
> solver, but not much progress has been made in that direction (see
> https://github.com/matplotlib/matplotlib/issues/1109)
> Tom
> On Fri, Mar 13, 2015 at 3:01 PM Ryan Nelson <rnelsonchem at gmail.com> wrote:
>> I'm constructing a multi-plot figure using an IPython notebook (v3) and
>> matplotlib (v1.4.3) inline magic. I was manually setting the axes bounds,
>> and I ended up with something like the following:
>> ########
>> import matplotlib.pyplot as plt
>> %matplotlib inline
>> bottom = 0.12
>> top = 0.9
>> left = 0.12
>> axwidth = (1-(left*2))/3
>> fig = plt.figure(figsize=(10,4))
>> ax1 = fig.add_axes((left, bottom, axwidth, top))
>> ax1.set_title('Title')
>> #ax1.tick_params(labelleft=False)
>> ax2 = fig.add_axes((left+axwidth, bottom, axwidth, top),
>>                    sharex=ax1, sharey=ax1)
>> ax2.tick_params(labelleft=False)
>> ax3 = fig.add_axes((left+axwidth*2, bottom, axwidth, top),
>>                    sharex=ax1, sharey=ax1)
>> ax3.tick_params(labelleft=False)
>> fig.savefig('junk.pdf', format='pdf')
>> fig.savefig('junk2.png')
>> #######
>> Obviously, the bottom+top that I've selected is >1, so the axes should go
>> off the top of the figure. (Stupid, I know...) The axes in both the PDF and
>> PNG formatted files are clipped by the top of the figure as you would
>> expect; however, the figure that is displayed in the Notebook looks just
>> fine. In addition, if you add a title to one of the axes, the figure in
>> IPython suddenly creates more space for the text. Maybe it is rearranging
>> the axes information behind the scenes?
>> I'm curious why this design decision was made. I would say this is a bug.
>> Now that I know about this behavior, I can easily fix it. But new users
>> will be baffled when their saved figure looks nothing like the displayed
>> figure in the notebook.
>> Ryan
>> ------------------------------------------------------------
>> ------------------
>> Dive into the World of Parallel Programming The Go Parallel Website,
>> sponsored
>> by Intel and developed in partnership with Slashdot Media, is your hub
>> for all
>> things parallel software development, from weekly thought leadership
>> blogs to
>> news, videos, case studies, tutorials and more. Take a look and join the
>> conversation now. http://goparallel.sourceforge.net/
>> _______________________________________________
>> Matplotlib-users mailing list
>> Matplotlib-users at lists.sourceforge.net
>> https://lists.sourceforge.net/lists/listinfo/matplotlib-users
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.python.org/pipermail/ipython-dev/attachments/20150313/bce1a5d6/attachment.html>

More information about the IPython-dev mailing list