Re: [Matplotlib-users] set limits not obeyed for stacked plots when set_aspect('equal') used

[Brendan B. <bre...@br...>]

On 2013-03-20 14:25, Eric Firing wrote:
> On 2013/03/20 8:57 AM, Jonathan Slavin wrote:
>> Hi all,
>>
>> I've run across a minor but annoying bug.  It can be demonstrated pretty
>> simply:
>>
>> fig, ax = plt.subplots(2,1,sharex=True,figsize=(7.,7.))
>> fig.subplots_adjust(hspace=0.0)
>> x = 4.25*(np.arange(6.) - 2.5)/10.
>> y =  0.6*x/max(x)
>> ax[0].plot(x,y)
>> ax[0].set_xlim(-1.2,1.2)
>> ax[0].set_aspect('equal')
>> ax[1].plot(x,y)
>> ax[0].set_ylim(-0.6,0.6)
>> ax[1].set_ylim(-0.6,0.6)
>> ax[1].set_aspect('equal')
>> plt.show()
>>
>> The problem is that the y limits on the two plots are slightly different
>> from those set:
>
> I think the problem is that you are trying to specify too many things:
> you are specifying the box dimensions when you make the axes, then you
> are specifying xlim, and then you are specifying ylim, but then you are
> asking for a 1:1 aspect ratio.  Something has to give!  The aspect ratio
> handling is designed to provide the specified aspect ratio under a wide
> range of circumstances, including zooming and panning, and to do that,
> it has to be able to change something.  You can choose to let the box
> dimensions be changeable, or the data limits.

	If I understand right, though, in this case what should give is the 
spacing around the axes but inside the figure (as suggested in the 
original post).  You should be able to fix the aspect ratio of the 
*axes* and also the dimensions of the *figure*, and let the slack be 
taken up by blank space around the axes.  It would still be possible 
for the dimensions of the axes box to change, just not their aspect 
ratio (i.e., zooming in on an oblong region would just result in a lot 
of blank space).

-- 
Brendan Barnwell
"Do not follow where the path may lead.  Go, instead, where there is 
no path, and leave a trail."
    --author unknown