bugGNU Octave - Bugs: bug #39642, flat shading on pcolor draws...


bug #39642: flat shading on pcolor draws pcolor above other plots

Submitter:  None
Submitted:  Thu 01 Aug 2013 12:41:55 PM UTC
Category:  Plotting with gnuplot Severity:  3 - Normal
Priority:  5 - Normal Item Group:  Incorrect Result
Status:  Fixed Assigned to:  None
Originator Name:  Originator Email:  -email is unavailable-
Open/Closed:  * Closed Release:  * dev
Operating System:  * GNU/Linux Fixed Release:  None
Planned Release:  None
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Mon 21 Nov 2016 10:46:27 PM UTC, comment #4: 

Agreed, works for me also with 4.2.0 and gnuplot 5. Going back to 4.0.3 shows that it still failed, so fixed somewhere between 4.0 and 4.2. Thanks for testing.

Mike Miller <mtmiller>
Project Administrator
Mon 21 Nov 2016 10:34:00 PM UTC, comment #3: 

I have tested this in Octave 4.2.0 and this issue seems to be FIXED now:

  • it works fine on (Ubuntu 14.04) linux (with gnuplot 4.6.4-2)
  • it works fine in WinXP with the official w32 installer.
Hartmut <hardy>
Thu 05 Sep 2013 03:03:36 AM UTC, comment #2: 

I can confirm the described behavior on the development version of Octave as well with gnuplot 4.6.3. Using FLTK instead shows a consistent stacking order with either shading type.

This isn't really a regression in Octave but rather some change with different versions of gnuplot. I am not familiar enough with the Octave gnuplot interface to know whether this can be fixed or if it should be reported to gnuplot instead.

Mike Miller <mtmiller>
Project Administrator
Thu 01 Aug 2013 02:17:31 PM UTC, comment #1: 

More investigations suggest this is a problem with gnuplot and/or gnuplot/octave interface.

The original bug report was with gnuplot Version: 4.4.3-0ubuntu3 in ununtu 12.04. Downgrading gnuplot to 4.2.6-1 (Lucid version) seems to avoid this bug.

Downgrading also avoids another bug I've just noticed where there are horizontal and vertical lines in pcolor plots (misalignment or inaccuracy) written to png format.

Thu 01 Aug 2013 12:41:55 PM UTC, original submission:  


[Fx,Fy] = gradient(Z);
shading interp;

hold on
p= plot([-10:1:10], [-10:1:10])

appears ok, but

shading flat;

draws the pcolor above the other plots. The order of the axis children doesn't change during this.



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  • -email is unavailable- added by mtmiller (Posted a comment)

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    Follow 5 latest changes.

    Date Changed by Updated Field Previous Value => Replaced by
    2016-11-21 mtmiller StatusConfirmed Fixed
        Open/ClosedOpen Closed
    2013-09-05 mtmiller Item GroupRegression Incorrect Result
        StatusNone Confirmed
        Release3.6.4 dev

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