Re: AspectRatio Patches [changeset]

[Ben Abbott]

On Oct 28, 2010, at 1:54 PM, Ben Abbott wrote:

> On Oct 28, 2010, at 11:57 AM, Ben Abbott wrote:
> 
>> On Oct 28, 2010, at 5:25 AM, logari81 wrote:
>> 
>>> On Wed, 2010-10-27 at 23:11 +0800, Ben Abbott wrote:
>>>> On Oct 27, 2010, at 10:38 PM, logari81 wrote:
>>>> 
>>>>> Hi all,
>>>>> 
>>>>> in continuation to:
>>>>> https://www-old.cae.wisc.edu/pipermail/octave-maintainers/2010-January/014960.html
>>>>> 
>>>>> now that the native graphics seem to have reached a pretty mature state,
>>>>> I think is the right moment to fix the daspect,pbaspect, axis square,
>>>>> axis equal issue, once for ever.
>>>>> 
>>>>> First of all we have to be sure that we all have the same understanding
>>>>> of what Matlab does. So please consider the following:
>>>>> 
>>>>> http://www.mathworks.com/help/techdoc/ref/daspect.html
>>>>> http://www.mathworks.com/help/techdoc/ref/axes_props.html
>>>>> http://www.mathworks.com/help/techdoc/visualize/f4-24991.html
>>>>> http://www.mathworks.com/help/techdoc/visualize/f4-48363.html
>>>>> 
>>>>> especially the table in the "DataAspectRatio" section of the second
>>>>> link.
>>>>> 
>>>>> I have invested some time in making octave (at least the fltk backend)
>>>>> behave similarly to Matlab. In the attached patch-files
>>>>> "octave_aspectratios_1.patch" and "octave_aspectratios_2.patch" you can
>>>>> find an implementation of the relation between dataaspectratio,
>>>>> plotboxaspectratio, xlim, ylim and zlim as it is described in the Matlab
>>>>> documentation.
>>>>> 
>>>>> The file "octave_genprops_comments.patch" includes a minor comment
>>>>> improvement.
>>>>> 
>>>>> An overview with test cases comparing octave before and after my
>>>>> modifications with Matlab can be found here:
>>>>> http://files.ubuntu-gr.org/forum/logari81/Bugs/comparison_aspectratios.pdf
>>>>> 
>>>>> The patches attached in this mail also replace the patch that I provided
>>>>> some days before as a fix for bug #30343:
>>>>> https://savannah.gnu.org/bugs/?30343 
>>>>> 
>>>>> TODO:
>>>>> 
>>>>> 1. After the adoption of the attached patches the "axis equal" command
>>>>> could be converted to be based on daspect instead of pbaspect, so that
>>>>> it is compatible with Matlab.
>>>>> 
>>>>> 2. The test case on page 5 of the above given pdf shows a problem with
>>>>> the modified version and the gnuplot backend. This should be fixed. In
>>>>> all other cases the modified version works better even for the gnuplot
>>>>> backend.
>>>>> 
>>>>> Please let me know what do you think about my proposals.
>>>>> 
>>>>> Best regards,
>>>>> 
>>>>> Kostas
>>>> 
>>>> I'll try to look at the effect of the patches tomorrow.
>>>> 
>>>> For now, without your patches, when I try ...
>>>> 
>>>> backend gnuplot
>>>> close all
>>>> plot (1:10)
>>>> set (gca, "activepositionproperty", "position")
>>>> pbaspect ([1, 3, 1])
>>>> print -dpdfwrite gp-pbaspect.pdf
>>>> 
>>>> ... I get the attached pdf. Why does your "original" and "modified" 
>>>> gnuplot results give such a different result? My tip is 11159. which I 
>>>> assume should be the same as your "original". Do you get this result as 
>>>> well.
>>>> 
>>>> Ben
>>>> 
>>>> p.s. When the "activepositionproperty" is set to "outerposition", Octave 
>>>> is unable to exactly detemine the size of the plot box, so when pbaspect 
>>>> is set, the result will deviate from what is desired. To fix the pbaspect 
>>>> correctly, the "activepositionproperty" needs to be set to "position".
>>>> 
>>> 
>>> Actually my changes are not related to the "activepositionproperty". If
>>> you refer to the very small plotbox in some of my screenshots, this is
>>> probably some other bug observed both in the original and the modified
>>> version. It has nothing to do with my modifications. Changing
>>> "activepositionproperty" doesn't improve the problem.
>> 
>> My mentioned of the activepositionproperty was just to explant that when it 
>> is set to outerposition the plotboxaspectratio be rendered improperly. This 
>> *feature* is due to lacking a method to determine the textextents for the 
>> text objects (including the ticklabels).
>> 
>>> I can confirm that my "original" version is 11159 as well, and running
>>> your test gives me the same result as in your gp-pbaspect.pdf .
>>> 
>>> What my patch is simply about, is adding daspect support. Currently in
>>> octave there is no real daspect support. Up to now octave just mimicked
>>> daspect behavior through pbaspect.
>> 
>> I'm partly responsible for the current behavior. When the axis limits (xlim 
>> or ylim), dataaspectratio, and plotboxaspectratio are all set, one of the 
>> three must yield to the others. I tried to mimic the behavior of Matlab, but 
>> it doesn't surprise me that I missed something.
>> 
>>> My changes where done with the fltk backend in mind. The setting of
>>> aspect ratios with this backend seems error free and absolutely
>>> consistent with Matlab. Concerning gnuplot, I consider its aspectratio
>>> behavior anyway broken, so I just tried to confirm a posteriori that I
>>> didn't make it worse. The only regression I found is shown on page 5. I
>>> will investigate it. In other cases my changes improved the behavior of
>>> the the gnuplot backend as well (e.g. pages 6, 7 and 8).
>> 
>> 
>> I'm having a bit of trouble following your graphical examples. For example, 
>> the pdf's you attached show a very small plot box for gnuplot, This seems to 
>> be in conflict with your confirmation that you get the same result as I for 
>> the example I gave.
>> 
>> Perhaps we can use a standard script. Is the attached one ok? I've attached 
>> the resulting pdf as well. From this script is the problem with how the 
>> gnuplot backend handles aspect ratios present? If not, can you provide a 
>> simple example that can be added to the demos?
>> 
>> I have another problem to look at before this one. I'll try applying the 
>> patches later.
>> 
>> Ben
>> 
>> <test_aspect.m><aspect_demos.pdf>
> 
> I'd forgotten that FLTK-aqua on MacOS X has a problem with initialization. 
> Please ignore the prior FLTK plots.
> 
> To detect conflicts between the data and plot box aspect ratios, I've added 
> tests to daspect.m and pbaspect.m which set both aspect ratios (the changeset 
> for that has been pushed).
> 
> I've also applied your patches, modified my test script to work around the 
> FLTK-aqua problem on MacOS X. The cumulative result is that the fltk backend 
> looks like it is doing the right thing, but the gnuplot behavior is not 
> correct when both the data and plot box aspect ratios are set.
> 
> I've attached both the updated test script, and the pdf it produces for me.
> 
> If there is no objection (from you or anyone else), I can push these changes 
> for you.
> 
> Ben
> 
> <test_aspect.m><aspect_demos.pdf>

Kostas, I've consolidated your patches and added an entry into the ChangeLog.  
Please confirm I've got your name correct, and that it is ok to push.

Ben

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