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

 
 

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

Submitted by:  None
Submitted on:  Tue 14 Apr 2015 12:03:38 AM UTC  
 
Category: PlottingSeverity: 3 - Normal
Priority: 5 - NormalItem Group: Incorrect Result
Status: DuplicateAssigned to: None
Originator Name: Richard LangOriginator Email: -unavailable-
Open/Closed: ClosedRelease: 3.8.2
Operating System: Microsoft Windows

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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>
Project 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)

 

Depends on the following items: None found

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  • -unavailable- added by rik5 (Posted a comment)
  • -unavailable- added by richardlang (Posted a comment)
  • -unavailable- added by None (Submitted the item)
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    Follow 3 latest changes.

    Date Changed By Updated Field Previous Value => Replaced By
    Tue 14 Apr 2015 02:05:13 AM UTCrik5StatusNone=>Duplicate
      Open/ClosedOpen=>Closed
    Tue 14 Apr 2015 12:03:38 AM UTCNoneAttached File-=>Added testPlot_datenum.m, #33669

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