[Pkg-octave-devel] [RFU] Several packages for jessie

[Rafael Laboissiere]

* Sébastien Villemot <sebastien at debian.org> [2013-05-20 14:46]:
>
> I uploaded all of them to unstable, except octave-image and octave-nurbs 
> which have failing tests. [snip]

I am revisiting the issue with octave-image.  According to your build 
log, one of the failures you observed is the following one:

     [imnoise]
       ***** assert(var(imnoise(ones(10)/2,'speckle')(:)),0.01,0.005) # probabilistic
     !!!!! test failed
     assert (var (imnoise (ones (10) / 2, 'speckle') (:)),0.01,0.005) expected
      0.010000
     but got
      0.015648
     maximum absolute error 0.00564816 exceeds tolerance 0.005

This test is probabilistic (as it is announced in the comment above). I 
ran a quick test to check the variability of the result:

     n = 10000;
     v = zeros (1, n);
     for i = 1 : n
          v (i) = var (imnoise (ones (10) / 2, 'speckle') (:));
     endfor
     length (find (abs (v - 0.01) > 0.005)) / n

The last line yields 0.0016.  This means that we got hit by an event with 
approximately 0.16% of happening.  This is a very low probability, but it 
is greater than zero and, indeed, has bitten us.

I am wondering how we should proceed about these probabilistic tests 
in our packages.

Rafael