# Create plot with multiple overlayed lines, where colorbar corresponds to color of line

182 views (last 30 days)
M1997 on 22 Jul 2019
Edited: Adam Danz on 10 Oct 2019
my goal is to create a colorbar to represent the colors of data lines plotted on a figure
the color of the lines follow the jet colormap pattern, so I feel this should be possible to do in Matlab.
for example:
time = 0:.1:5; %seconds
A = 10: %number of plots
plotColor = jet(A); %Creates a 10 by 3 matrix of colors transitioning from dark blue to dark red.
figure
for H = 1:A
plot( H*sin(time), 'color', plotColor(:,H) )
hold on
end
In this example I want to have a color bar to represent the height of the sine wave as a function of the color of the lines.
I haven't been able to figure out a way to implement this yet and I would appreciate any help! Thank you in advance.
Hans123 on 22 Jul 2019
The reason you did not get colored plots was because you referenced the newly created color array in the incorrect way - all the rows of column H
plot( H*sin(time), 'color', plotColor(:,H) )
It should be all the columns (RGB) of row H
plot( H*sin(time), 'color', plotColor(H,:) )
Hope that cleared out any confusion

Hans123 on 22 Jul 2019
Edited: Hans123 on 22 Jul 2019
Hope this helps
clc; close; clear
time = 0:0.1:5; %seconds
A = 10; %number of plots
colormap(jet(10))
jetcustom = jet(10);
figure
for H = 1:A
plot(time,H*sin(time), 'Color', jetcustom(H,:))
hold on
end
xlabel('Time (s)')
colormap(jet(10))
cb = colorbar;
caxis([-10 10])
ylabel(cb,'Height')
##### 2 CommentsShowHide 1 older comment
Hans123 on 23 Jul 2019
Glad I could be of help.

Adam Danz on 9 Oct 2019
Edited: Adam Danz on 10 Oct 2019
In addition to Hans' method, you can also apply the colorbar based on whatever line colors are already set up in the "ColorOrder" property of your axes.
% Create demo plot
figure()
hold on
for i = 1:15
plot([0,1],[i,i],'-','LineWidth',2)
end
% Get the axis handle and the number of lines drawn
% Usually you can skip this step because you already have
% these two variables.
axh = gca();
nLines = length(findall(axh,'Type','line'));
% Produce a colormap based on the ColorOrder of the axis
cmap = axh.ColorOrder;
cmap = repmat(cmap, ceil(nLines/size(cmap,1)), 1);
colormap(axh,cmap(1:nLines,:));
cbh = colorbar();
caxis([1,nLines+1]) % tick number 'n' is at the bottom of the n_th color
ylabel(cbh,'Line number') R2019a

### Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!