There was an error in camroll (and apparently in earlier Matlab versions) that the dataaspectratio was not considered. The attached patch should fix that error and allows the tests to pass with the updated reference values from recent Matlab versions.

It should be save to apply this patch on stable because no big changes are made (and it fixes a bug).

That still leaves the original issue why the tests need broader tolerances on 32bit architectures. But that definitely has time for after 4.4 is released.

(file #43840)

But error is just a way off...
I thought meya be there is a typo somewhere.

Dmitri.

I just saw on stable buildbot:

http://buildbot.octave.org:8010/builders/stable-gcc-fedora/builds/6/steps/test/logs/stdio

>>>>> processing /home/buildbotu/fc25-x86_64/stable-gcc-fedora/src/scripts/plot/appearance/camroll.m
***** test
 hf = figure ("visible", "off");
 unwind_protect
   peaks ();
   p = camup ();
   assert (p, [0 0 1], eps);
   camroll (30);
   p = camup ();
   ## from Matlab R2014a
   q = [0.826398839602911  0.255644120004753  0.50170812412194];
   ## from Matlab R2016a
   q = [0.33969638129660373 0.02014238382998192 0.94031944194919104];
   assert (p, q, 10*eps);
   camroll (-30);
   ## note it does not go back to [0 0 1]: instead orthog to camera view:
   p = camup ();
   ## The following assert doesn't seem to have any validation in Matlab R2016a
   assert (dot (p, camtarget () - campos ()), 0, 32*eps);  # FIXME: looser tolerance needed on i386
   ## from Matlab R2014a
   q = [0.496200420425837  0.646660977913424  0.57932264103285];
   ## from Matlab R2016a
   q = [0.14033891839365262 0.18289323924769943 0.97306477226420207];
   assert (p, q, 10*eps);
 unwind_protect_cleanup
   close (hf);
 end_unwind_protect
!!!!! test failed
ASSERT errors for:  assert (p,q,10 * eps)

  Location  |  Observed  |  Expected  |  Reason
    (1)         0.8264       0.3397      Abs err 0.4867 exceeds tol 2.2204e-15 by 0.5
    (2)        0.25564      0.020142     Abs err 0.2355 exceeds tol 2.2204e-15 by 0.2
    (3)        0.50171      0.94032      Abs err 0.43861 exceeds tol 2.2204e-15 by 0.4

Dmitri.
--

The attached patch updates the references to the highest possible precision as seen in Matlab R2016a.

Most changes only add a few more decimals. But the test in camroll.m gives very different results from the previous ones (R2014a):

## test rolling, then rolling back
%!test
%! hf = figure ("visible", "off");
%! unwind_protect
%!   peaks ();
%!   p = camup ();
%!   assert (p, [0 0 1], eps);
%!   camroll (30);
%!   p = camup ();
%!   ## from Matlab R2014a
%!   q = [0.826398839602911  0.255644120004753  0.50170812412194];
%!   ## from Matlab R2016a
%!   q = [0.33969638129660373 0.02014238382998192 0.94031944194919104];
%!   assert (p, q, 10*eps);
%!   camroll (-30);
%!   ## note it does not go back to [0 0 1]: instead orthog to camera view:
%!   p = camup ();
%!   ## The following assert doesn't seem to have any validation in Matlab R2016a
%!   assert (dot (p, camtarget () - campos ()), 0, 32*eps);  # FIXME: looser tolerance needed on i386
%!   ## from Matlab R2014a
%!   q = [0.496200420425837  0.646660977913424  0.57932264103285];
%!   ## from Matlab R2016a
%!   q = [0.14033891839365262 0.18289323924769943 0.97306477226420207];
%!   assert (p, q, 10*eps);
%! unwind_protect_cleanup
%!   close (hf);
%! end_unwind_protect

The on-screen results in R2016a seem to be reasonable. Maybe someone with a newer Matlab version might be able to check whether this is only an error in Matlab R2016a on Windows 10 64bit.

Code to execute:

hf = figure;
peaks ();
p = camup ();
fprintf ('%.17f\n', p);
camroll (30);
p = camup ();
fprintf ('%.17f\n', p);
camroll (-30);
p = camup ();
fprintf ('%.17f\n', p);

(file #43783)

@Mike: I won't be able to check in Matlab probably for a week or two. But go ahead and push your patch.
I'll try and get results with more significant digits later. But as I understand our GL based graphics are single precision anyway (and the differences are very minor). Thus, relaxing the tolerance is totally fine.

I am guessing the underlying issue is that some trigonometric functions give slightly different results on different platforms. I believe there is a bug report about this somewhere. But I cannot find it right now.

Markus, do you have access to Matlab to get updated constants for the tests? Besides these test failures, I see explicit floating point constants from Matlab in tests for camlookat.m, camorbit.m, camroll.m, camzoom.m, and camlight.m. Matlab doesn't have printf, so that would be sprintf.

If you think this will take a while to investigate or don't have time now, I will just increase the tolerances for now and leave this report open, as with bug #53438.

I'd be happy to test further if you can tell me what to run.

Here's the output from running the minimal commands directly to show the camorbit results that are different:

>> hf = figure ('visible', 'off');
>> sphere ();
>> camorbit (20, 30, 'data', [1, 2, 3]);
>> p = get (gca, 'cameraposition');
>> format long
>> p.'
ans =

  -2.157726725251017e-01
  -9.049266154288148e+00
   1.476699780668523e+01

In testing Octave built for i686, I am seeing 1 test failure in camorbit.m and 1 test failure in camroll.m.

Both test failures look like candidates for increasing the tolerances, if someone familiar with these functions can verify that this makes sense.

 hf = figure ("visible", "off");
 unwind_protect
   sphere ();
   camorbit(20, 30, "data", [1 2 3]);
   p = campos ();
   u = camup ();
   ## Matlab 2014a
   pm = [-0.215772672525099  -9.04926615428815  14.7669978066852];
   um = [0.413058199972826  0.773801198226611  0.48022351989284];
   assert (p, pm, -5e-15);
   assert (u, um, -5e-15);
 unwind_protect_cleanup
   close (hf);
 end_unwind_protect
!!!!! test failed
ASSERT errors for:  assert (p,pm,-5e-15)

  Location  |  Observed  |  Expected  |  Reason
    (1)        -0.21577     -0.21577     Rel err 1.2477e-14 exceeds tol 5e-15 by 7e-15


 hf = figure ("visible", "off");
 unwind_protect
   peaks ();
   p = camup ();
   assert (p, [0 0 1], eps);
   camroll (30);
   p = camup ();
   ## from Matlab R2014a
   q = [0.826398839602911  0.255644120004753  0.50170812412194];
   assert (p, q, 10*eps);
   camroll (-30);
   ## note it does not go back to [0 0 1]: instead orthog to camera view:
   p = camup ();
   assert (dot (p, camtarget () - campos ()), 0, eps);
   q = [0.496200420425837  0.646660977913424  0.57932264103285];
   assert (p, q, 10*eps);
 unwind_protect_cleanup
   close (hf);
 end_unwind_protect
!!!!! test failed
ASSERT errors for:  assert (dot (p, camtarget () - campos ()),0,eps)

  Location  |  Observed  |  Expected  |  Reason
     ()      -4.3993e-15       0         Abs err 4.3993e-15 exceeds tol 2.2204e-16 by 4e-15