bugGNU Octave - Bugs: bug #44827, FLTK: Plot() broken when close...

 
 

bug #44827: FLTK: Plot() broken when close together datenum values used on X axis

Submitter:  None
Submitted:  Tue 14 Apr 2015 12:03:38 AM UTC
   
 
Category:  Plotting Severity:  3 - Normal
Priority:  5 - Normal Item Group:  Incorrect Result
Status:  Duplicate Assigned to:  None
Originator Name:  Richard Lang Originator Email:  -email is unavailable-
Open/Closed:  * Closed Release:  * 3.8.2
Operating System:  * Microsoft Windows Fixed Release:  None
Planned Release:  None
* Mandatory Fields

Add a New Comment Rich Markup
   

Tue 14 Apr 2015 02:05:13 AM UTC, comment #2: 

This is a known problem with OpenGL which uses single precision variables.  See bug #32980 and bug #37553.  Current workaround is re-scaling manually or switching to gnuplot.

Rik <rik5>
Group administrator
Tue 14 Apr 2015 12:32:08 AM UTC, comment #1: 

Perhaps due to FLTK using single precision floating point numbers internally and dropping most of the fractional component when passed datenums representing contemporary date-times?

So maybe not a bug as such, but don't imagine I'm the first or last person that's going to trip over this.  Perhaps some datenum specific guard code in plot(), or at least a warning in the documentation might be appropriate?

Richard Lang <richardlang>
Tue 14 Apr 2015 12:03:38 AM UTC, original submission:  

MXE-Octave 3.8.2 running on Windows 7 - About dialog tells me it is configured for "i686-w64-mingw32"

Using default FLTK graphics toolkit

plot() seems to cope fine with a set of datenum x values that specify date-times that are days or weeks apart, but falls to bits when fed a set that vary by seconds

Illustrative script attached


All appears to work OK when I switch to gnuplot


Anonymous

 

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Attached Files
file #33669:  testPlot_datenum.m added by None (1KiB - text/x-objcsrc)

 

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    Follow 3 latest changes.

    Date Changed by Updated Field Previous Value => Replaced by
    2015-04-14 rik5 StatusNone Duplicate
        Open/ClosedOpen Closed
    2015-04-14 None Attached File- Added testPlot_datenum.m, #33669

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