bugGNU Octave - Bugs: bug #35033, mangled filled contour plot


bug #35033: mangled filled contour plot

Submitted by:  Ben Abbott <bpabbott>
Submitted on:  Sun 11 Dec 2011 06:43:39 PM UTC  
Category: PlottingSeverity: 3 - Normal
Priority: 5 - NormalItem Group: Incorrect Result
Status: FixedAssigned to: None
Originator Name: Ben AbbottOpen/Closed: Closed
Release: devOperating System: Any

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Fri 18 Nov 2016 08:32:48 PM UTC, comment #3:

I am closing this bug as fixed. The example in comment #1 behaves correctly in the current version of Octave (4.2.0).

The original example still has problems, but they appear to be solely due to bug #37501, because the input data contains NaN values. If I replace all NaNs in the ZI matrix with 0, then the plot appears correct.

Mike Miller <mtmiller>
Project Administrator
Sun 11 Dec 2011 07:20:13 PM UTC, comment #2:

The approximate correct result may be rendered using "imagesc (z)"

Ben Abbott <bpabbott>
Project Member
Sun 11 Dec 2011 07:14:24 PM UTC, comment #1:

Another example is below

Ben Abbott <bpabbott>
Project Member
Sun 11 Dec 2011 06:43:39 PM UTC, original submission:

This bug was found by Walter White <homerun4711@googlemail.com> on posted to help-octave Octave <Help-octave@octave.org>.

Walter found that Octave mangles the filled contour for his complicated example.

I verified that Octave and Matlab produce similar equivalent results for contour(), so only the filled version is impacted.

I've attached he m-file (walter.m) which may be used to produce the plot. Results for Matlab R2011b and Octave (tip: de90542b7afc) have been attached.

My impression is that the problem is with _contour_.m

Ben Abbott <bpabbott>
Project Member


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

Attach File(s):

Attached Files
file #24562:  walter.m added by bpabbott (617B - application/octet-stream)
file #24563:  my_FEM_matrix.txt added by bpabbott (807KiB - text/plain)
file #24564:  Walter-Octave.png added by bpabbott (302KiB - image/png)
file #24565:  Walter-MATLAB.png added by bpabbott (61KiB - image/png)


   bug dependencies.

Items that depend on this one: None found


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  • -unavailable- added by mtmiller (Posted a comment)
  • -unavailable- added by bpabbott (Submitted the item)

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    Follow 7 latest changes.

    Date Changed By Updated Field Previous Value => Replaced By
    Fri 18 Nov 2016 08:33:04 PM UTCmtmillerDependencies-=>Depends on bugs #37501
    Fri 18 Nov 2016 08:32:48 PM UTCmtmillerStatusNone=>Fixed
    Sun 11 Dec 2011 06:43:39 PM UTCbpabbottAttached File-=>Added walter.m, #24562
      Attached File-=>Added my_FEM_matrix.txt, #24563
      Attached File-=>Added Walter-Octave.png, #24564
      Attached File-=>Added Walter-MATLAB.png, #24565

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