Re: AspectRatio Patches

[Ben Abbott]

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".

gp-pbaspect.pdf
Description: Adobe PDF document