axis distortion in 3D plot

[Robert Gragg]

*** ENVIRONMENT ***

OS X Version 10.8.4

GNU Octave, version 3.2.4

Octave was configured for "i386-apple-darwin12.4.0".

G N U P L O T

Version 4.6 patchlevel 3    last modified 2013-04-12 

Build System: Darwin x86_64

*** OCTAVE SCRIPT ***

figure(1)

set(gcf,'Color',[1,1,1]);

[x,y,z] = sphere(40);

h = surf(x,y,z);

set(h,'facecolor','none','edgecolor',0.6*[1,1,1], ...

      'linestyle',':');

*** PROBLEM ***

Judged by the axis limits, the shape that this script plots on the monitor is a unit sphere.  But it looks more like an oblate spheroid [see attached PDF].  I thought the following line might fix this, but it had no effect.  

set (gca, "PlotBoxAspectRatioMode", "manual", ...

          "PlotBoxAspectRatio", [1, 1, 1]);

 

In the work I'm trying to do, it's important to avoid this kind of distortion.  

I used to be able to do it in Matlab but I don't see the answer in Octave.  

sphere.pdf
Description: Adobe PDF document