[Octave-bug-tracker] [bug #33177] contourf with LVL = [0,0]

[Marco Caliari]

URL:
  <http://savannah.gnu.org/bugs/?33177>

                 Summary: contourf with LVL = [0,0]
                 Project: GNU Octave
            Submitted by: caliari
            Submitted on: Thu 28 Apr 2011 14:00:42 GMT
                Category: Plotting
                Severity: 3 - Normal
                Priority: 5 - Normal
              Item Group: Incorrect Result
                  Status: None
             Assigned to: None
         Originator Name: 
        Originator Email: 
             Open/Closed: Open
         Discussion Lock: Any
                 Release: 3.4.0
        Operating System: GNU/Linux

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Details:

Dear maintainers,

the following code


x = linspace(-2,2);
[X,Y] = meshgrid(x);
lvl = 1;
contourf(X.^2+Y.^2-1,[lvl,lvl])


draws a red disk (well, an ellipse) for any value of lvl BUT 0. The problem is
in the function get_lvl_eps inside __contour__.m, which sets lvl_eps to 0. If
you add a sqrt(eps) to lvl_eps as an absolute tolerance, the disk is drawn for
lvl = 0, too. I'm enclosing a patch.

Marco



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File Attachments:


-------------------------------------------------------
Date: Thu 28 Apr 2011 14:00:42 GMT  Name: __contour__.m.diff  Size: 105B   By:
caliari

<http://savannah.gnu.org/bugs/download.php?file_id=23318>

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