bugGNU Octave - Bugs: bug #51986, [octave forge] (image) Failing...

 
 

bug #51986: [octave forge] (image) Failing unit test for cp2tform

Submitter:  Rafael Laboissière <rlaboiss>
Submitted:  Sun 10 Sep 2017 07:11:44 PM UTC
 
Category:  Octave Forge Package Severity:  3 - Normal
Priority:  5 - Normal Item Group:  Incorrect Result
Status:  Fixed Assigned to:  None
Originator Name:  Open/Closed:  * Closed
Release:  * other Operating System:  * Any
* Mandatory Fields

Add a New Comment (Rich Markup)
   

Comment Type & Canned Response:
       

 

Tue 21 Nov 2017 09:37:27 AM UTC, comment #4: 

Thank you. I have adjusted the tolerance accordingly.
http://hg.code.sf.net/p/octave/image/rev/22ca8c0ee911

Carnë Draug <carandraug>
Project Member
Sun 12 Nov 2017 09:20:52 PM UTC, comment #3: 

Running 4.2.1 32 bit version on Windows machine,
I have found that the first test (projective) needs slightly more than one eps.  2*eps will suffice.

The last test (polynomial, ord=4) needs 6*eps

Avinoam Kalma <avinoam>
Project Member
Fri 10 Nov 2017 12:53:14 PM UTC, comment #2: 

I couldn't reproduce this after 500 iterations. Maybe because I'm running in x86-64 ?

If the issue is i386 only, could you please suggest an appropriate tolerance value.

Carnë Draug <carandraug>
Project Member
Thu 09 Nov 2017 08:14:13 PM UTC, comment #1: 

It seems like a tolerance problem. Increasing the tolerance will stop these random fails.

Avinoam Kalma <avinoam>
Project Member
Sun 10 Sep 2017 07:11:44 PM UTC, original submission:  

The following units test for function cp2tform in package image fail randomly:

+verbatim
%!test
%! npt = 100000;
%! [crw, cap] = coords (npt);
%! ttype = 'projective';
%! T = cp2tform (crw, cap, ttype);
%! crw2 = tforminv (T, cap);
%! finalerr = norm (crw - crw2)/npt;
%! assert (finalerr < eps, "norm = %3.2e ( > eps)", finalerr)

%!test
%! npt = 100000;
%! [crw, cap] = coords (npt);
%! ttype = 'affine';
%! T = cp2tform (crw, cap, ttype);
%! crw2 = tforminv (T, cap);
%! finalerr = norm (crw - crw2)/npt;
%! assert (finalerr < eps, "norm = %3.2e ( > eps)", finalerr)

%!test
%! npt = 100000;
%! [crw, cap] = coords (npt);
%! ttype = 'nonreflective similarity';
%! T = cp2tform (crw, cap, ttype);
%! crw2 = tforminv (T, cap);
%! finalerr = norm (crw - crw2)/npt;
%! assert (finalerr < eps, "norm = %3.2e ( > eps)", finalerr)

%!test
%! npt = 100000;
%! [crw, cap] = coords (npt);
%! cap(:,2) *= -1; % reflection around y axis
%! ttype = 'similarity';
%! T = cp2tform (crw, cap, ttype);
%! crw2 = tforminv (T, cap);
%! finalerr = norm (crw - crw2)/npt;
%! assert (finalerr < eps, "norm = %3.2e ( > eps)", finalerr)

+verbatim+
octave:1> pkg load image
octave:2> function [crw, cap] = coords (npt = 1000, scale = 2, dtheta = pi/3, dx = 2, dy = -6, sig2noise = 1e32)
  theta = (rand(npt, 1)*2-1)*2*pi;
  R = rand(npt,1);
  y = R.*sin(theta);
  x = R.*cos(theta);
  crw = [y x];

  thetap = theta + dtheta;
  Rap = R * scale;

  yap = Rap.*sin(thetap);
  yap = yap + dy;
  yap = yap + rand (size (yap)) * norm (yap) / sig2noise;

  xap = Rap.*cos(thetap);
  xap = xap + dx;
  xap = xap + rand (size (xap)) * norm (xap) / sig2noise;
  cap = [yap xap];
endfunction

while 1
 npt = 100000;
 [crw, cap] = coords (npt);
 cap(:,2) *= -1;        % reflection around y axis
 ttype = 'similarity';
 T = cp2tform (crw, cap, ttype);
 crw2 = tforminv (T, cap);
 finalerr = norm (crw - crw2)/npt;
 assert (finalerr < eps, "norm = %3.2e ( > eps)", finalerr)
endwhile
error: norm = 2.25e-16 ( > eps)
error: called from
    assert at line 94 column 11


This is an example of how the bug can be triggered:


Rafael Laboissière <rlaboiss>

 

(Note: upload size limit is set to 16384 kB, after insertion of the required escape characters.)

Attach Files:
   
   
Comment:
   

No files currently attached

 

Depends on the following items: None found

Items that depend on this one: None found

 

Carbon-Copy List
  • -email is unavailable- added by avinoam (Posted a comment)
  • -email is unavailable- added by avinoam
  • -email is unavailable- added by rlaboiss (Submitted the item)
  •  

    There are 0 votes so far. Votes easily highlight which items people would like to see resolved in priority, independently of the priority of the item set by tracker managers.

    Only project members can vote.

     

     

     

     

    Follow 3 latest changes.

    Date Changed by Updated Field Previous Value => Replaced by
    2017-11-21 carandraug StatusNone Fixed
        Open/ClosedOpen Closed
    2017-11-09 avinoam Carbon-Copy- Added -email is unavailable-

    Back to the top


    Powered by Savane 3.9