[Octave-bug-tracker] [bug #59589] default color in bar (and hist) plots is different from Matlab

[Hartmut]

URL:
  <https://savannah.gnu.org/bugs/?59589>

                 Summary: default color in bar (and hist) plots is different
from Matlab
                 Project: GNU Octave
            Submitted by: hardy
            Submitted on: Tue 01 Dec 2020 05:17:09 PM UTC
                Category: Plotting
                Severity: 3 - Normal
                Priority: 5 - Normal
              Item Group: Matlab Compatibility
                  Status: None
             Assigned to: None
         Originator Name: 
        Originator Email: 
             Open/Closed: Open
                 Release: 6.1.0
         Discussion Lock: Any
        Operating System: Any

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Details:

This report is about the color used in bar() and hist() plots, when used
without any additional color options. In this case the colors in Octave (both
intense violet) are different from the colors used in Matlab plots (light and
dark blue). This might be connected to the change of default colormap to
viridis some time ago.

Here is code to reproduce the behavior. I will also attach two SCREENSHOTS
showing the resulting plots in Octave (6.1) and Matlab (R2019b) respectively:


clear, close all, clc
x = rand(1,20);

% color in bar plot:
figure(1)
hbar = bar(x);
title('bar');
barcolor = get(hbar, 'FaceColor')
% result in Matlab: [0 0.447 0.741] (light blue)
% result in Octave: 'flat', and via Gimp on screenshot: [0.267, 0.400, 0.329]
(violet)

% idea where this color (in Matlab) comes from: (light blue)
colororder = get(gca, 'ColorOrder');
colororder1 = colororder(1,:)
% result (in Matlab and Octave): [0 0.477, 0.741] (light blue)

% color in hist plot
figure(2)
hbar2 = bar(x, 'hist'); % which I think is the same as: hist(x)
title('hist');
histcolor = get(hbar2, 'FaceColor')
% result in Matlab: 'flat', and via Gimp on screenshot: [0.239, 0.149, 0.659]
(dark blue)
% result in Octave: 'flat', and via Gimp in screenshot: [0.267, 0.400, 0.329]
(violet)


This might mostly be an aesthetic problem, since one can always change the
colors used by Octave plots. Nevertheless this "aggressivly" violet color used
by Octave doesn't fit well into the colors used in most other Octave plots and
has therefore bothered my for quite some time already.



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File Attachments:


-------------------------------------------------------
Date: Tue 01 Dec 2020 05:17:09 PM UTC  Name: Screenshot_Matlab.png  Size:
39KiB   By: hardy

<http://savannah.gnu.org/bugs/download.php?file_id=50368>
-------------------------------------------------------
Date: Tue 01 Dec 2020 05:17:09 PM UTC  Name: Screenshot_Octave.png  Size:
35KiB   By: hardy

<http://savannah.gnu.org/bugs/download.php?file_id=50369>

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