bugGNU Octave - Bugs: bug #50417, overplotting contour over imagesc...


bug #50417: overplotting contour over imagesc fails (gnuplot)

Submitted by:  ryusuke numata <rnumata>
Submitted on:  Tue 28 Feb 2017 08:49:40 AM UTC  
Category: Plotting with gnuplotSeverity: 3 - Normal
Priority: 5 - NormalItem Group: Unexpected Error
Status: FixedAssigned to: None
Originator Name: Open/Closed: Closed
Release: 4.2.1Operating System: Any

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Wed 13 Dec 2017 04:47:49 PM UTC, comment #3:

This bug has been fixed on the stable branch an will be part of the 4.2.2 bug fix release due at the end of this year.

Rik <rik5>
Project Administrator
Tue 28 Feb 2017 08:00:24 PM UTC, comment #2:

This looks like something that was never tested upon making some kind of change to address something specific to the Qt gnuplot terminal.

Here's what Octave generates for gnuplot to process:

There is a continuation character ('\') at the end of the plot command, then some separate gnuplot command conditional which has nothing to do with the plot command, then a new plot command. That obviously is wrong.

Here's the code from _gnuplot_draw_axes_.m that generate the offending lines:

The logic here is obviously wrong, given there is no special consideration just a few lines above that would leave off the continuation character ('\'). I will look into this.

Dan Sebald <sebald>
Tue 28 Feb 2017 04:57:45 PM UTC, comment #1:

Confirmed. I used gnuplot 5.0.1 on Linux for testing. This is just one of the reasons that Octave development has moved away from gnuplot towards qt. As a workaround use one of the OpenGL toolkits such as qt or fltk.

When running the sample code I get the following errors

There are pages and pages of similar errors which all seem to show binary input from Octave delivered to the multiplot command line.

Rik <rik5>
Project Administrator
Tue 28 Feb 2017 08:49:40 AM UTC, original submission:

When I overplot contour over imagesc, I get lots of unreadable errors and a wrong image as attached.

The same code with graphics_toolkit('qt') seems working fine.

For older versions of octave (4.0.3), contour lines are not shown for both graphics toolkits.

I'm using gnuplot 5.0, I've tested on mac and linux.

ryusuke numata <rnumata>


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Attach File(s):

Attached Files
file #39846:  error.tiff added by rnumata (27KiB - image/tiff)
file #39847:  contour_imagesc.png added by rnumata (22KiB - image/png)


Depends on the following items: None found

Items that depend on this one: None found


Carbon-Copy List
  • -unavailable- added by rik5 (Posted a comment)
  • -unavailable- added by sebald (Posted a comment)
  • -unavailable- added by rik5
  • -unavailable- added by rnumata (Submitted the item)

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    Follow 10 latest changes.

    Date Changed By Updated Field Previous Value => Replaced By
    Wed 13 Dec 2017 04:47:49 PM UTCrik5StatusConfirmed=>Fixed
    Tue 28 Feb 2017 04:58:01 PM UTCrik5Carbon-CopyRemoved 72865=>-
    Tue 28 Feb 2017 04:57:45 PM UTCrik5StatusNone=>Confirmed
      Summaryoverplotting contour over imagesc fails=>overplotting contour over imagesc fails (gnuplot)
      Carbon-Copy-=>Added sebald
    Tue 28 Feb 2017 08:49:40 AM UTCrnumataAttached File-=>Added error.tiff, #39846
      Attached File-=>Added contour_imagesc.png, #39847
      Attached File-=>Added contour_imagesc_4.0.3.png, #39848

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