AspectRatio Patches

[logari81]

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

octave_aspectratios_1.patch
Description: Text Data

octave_aspectratios_2.patch
Description: Text Data

octave_genprops_comments.patch
Description: Text Data