[Octave-bug-tracker] [bug #45541] Automatically scale values before plotting

[anonymous]

URL:
  <http://savannah.gnu.org/bugs/?45541>

                 Summary: Automatically scale values before plotting
                 Project: GNU Octave
            Submitted by: None
            Submitted on: mån 13 jul 2015 11.56.08
                Category: Plotting with OpenGL
                Severity: 3 - Normal
                Priority: 5 - Normal
              Item Group: Incorrect Result
                  Status: None
             Assigned to: None
         Originator Name: 
        Originator Email: 
             Open/Closed: Open
         Discussion Lock: Any
                 Release: 3.8.1
        Operating System: Any

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Details:

This is a known problem but it has a solution:

>From the manual
    Caution: The FLTK toolkit uses single precision variables internally which
limits the maximum value that can be displayed to approximately 10^{38}. If
your data contains larger values you must use the gnuplot toolkit which
supports values up to 10^{308}.

The solution is to not pass values directly to FLTK. First scale them to fit
within [-1,1] and draw the axis with labels formatted from the original
values. The choice of feeding directly have other bad effects which occurs for
time series with a fairly large offset (see figure). It is strange that line
drawing is affected but not points.



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File Attachments:


-------------------------------------------------------
Date: mån 13 jul 2015 11.56.08  Name: skärmdump1.png  Size: 17 kB   By: None
Figure illustrating the bug
<http://savannah.gnu.org/bugs/download.php?file_id=34430>

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