Unique color for every plot line

To identify every line in a legend i want it to have a unique color.

as you can see, is already tried some. I'm still learning to use Matlab, so excuse me for my bad coding...

clear vars
close all

load 'Y:\Geovib\08\matlab.mat';

%afstand = '10m';   node='n201'; rij=2;
%afstand = '10.8m'; node='n202'; rij=3
%fstand = '11.6m';  node='n203'; rij=4;
%afstand = '12.7m'; node='n204'; rij=5;
%afstand = '13.3m'; node='n205'; rij=6;
%afstand = '14.3m'; node='n206'; rij=7
%afstand = '15.5m'; node='n207'; rij=8
%afstand = '16.8m'; node='n208'; rij=9
%afstand = '18.5m'; node='n209'; rij=10
%afstand = '20m';   node='n210'; rij=11
%afstand = '22m';   node='n211'; rij=12
%afstand = '24m';   node='n212'; rij=13
%afstand = '26.5m'; node='n213'; rij=14
%afstand = '29m';   node='n214'; rij=15
%afstand = '32m';   node='n215'; rij=16
afstand = 'alle';   node='alle';
%afstand = 'test';

   %%%%%%%%%%%%%%%

matlab.Properties.VariableNames{1} = 'time';
matlab = removevars(matlab, {'VarName29','VarName27','VarName25','VarName23','VarName21','VarName19','VarName17','VarName15','VarName13','VarName11','VarName9','VarName7','VarName5','VarName3'});
matlab.Properties.VariableNames{2} = 'n201';matlab.Properties.VariableNames{3} = 'n202';matlab.Properties.VariableNames{4} = 'n203';matlab.Properties.VariableNames{5} = 'n204';
matlab.Properties.VariableNames{6} = 'n205';matlab.Properties.VariableNames{7} = 'n206';matlab.Properties.VariableNames{8} = 'n207';matlab.Properties.VariableNames{9} = 'n208';matlab.Properties.VariableNames{10} = 'n209';
matlab.Properties.VariableNames{11} = 'n210';matlab.Properties.VariableNames{13} = 'n212';matlab.Properties.VariableNames{12} = 'n211';
matlab.Properties.VariableNames{14} = 'n213';matlab.Properties.VariableNames{15} = 'n214';matlab.Properties.VariableNames{16} = 'n215';matlab.Properties.VariableNames{16} = 'n215';
matlab.time(2) = 0;
matlab(1,:) = [];

   %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

%vars={'n201','n202','n203','n204','n205','n206','n207','n208','n209','n210','n211','n212','n213','n214','n215'};
vars={'10.0m','10.8m','11.6m','12.7m','13.3m','14.3m','15.5m','16.8m','18.5m','20.0m','22.0m','24.0m','26.5m','29.0m','32.0m'};

if isequal(afstand,'alle')  
    data_time = table2array(matlab(3:end,2:end)); 
else
    data_time = table2array(matlab(3:end,rij)); %%origineel
    vars=node;
end

time = matlab.time(3:end);
data_fft = fft(data_time);
Y = 2*abs(data_fft(2:end/2+1,:));

freqs = 1:1000/2;

figure
subplot(211)

semilogx(freqs,Y)

if isequal(afstand,'alle')

else
    title({['Afstand ',afstand, ' - node ',node]});
end

xlabel('frequentie [Hz]')
ylabel('trillingssnelheid(rms) [mm/s]')
colormap(hsv)
legend(vars)
% for i = 1:length(vars)
%     legend(i)
%     return
%     
% end
grid on;
hold on;
axis tight;
xlim([0 100])
ylim([0 0.000040])
%%%Subplot in tijddomein

subplot(212)
%plot(time,data_time(:,1:1:end),'color',rand(1,3))  % je kan ook een aantal lijnen plotten bijv. [1:5:7]
plot(time,data_time)
legend(vars)
colormap(prism)

%legend(unique(vars))

grid on;
axis tight;
hold on;
%ylim([-0.00000043 0.00000055])

clear node rij time Y  afstand data_fft matlab2

Answer 1

[jonas]

Here's an example that will give you truly unique colors from a colormap of your choice.

% Create 10 data series
XY = rand(100,10)

% Build colormap and shuffle
cmap = colormap(jet(size(XY,2)));
cmap = cmap(randperm(length(cmap)),:)

%Set colororder and plot
ax = axes('colororder',cmap);hold on
plot(XY)

I shuffled the colors (randperm) to make them random in the sense that the lines swap colors every time you plot. If the color has some significance, then you may want to remove that line. For example, you could design your plot so that the intensity of the line color represents the "quantity" of each line (10.0m, 10.8m, etc..). However, in that case it may be better to just go for the 3d plot instead :)

[Jesse]

Thanks! How does this work when i use my plot?

[Stephen23]

A better colormap would significantly improve this answer.

https://blogs.mathworks.com/steve/2014/10/13/a-new-colormap-for-matlab-part-1-introduction/

https://blogs.mathworks.com/steve/2014/10/20/a-new-colormap-for-matlab-part-2-troubles-with-rainbows/

https://blogs.mathworks.com/steve/2014/11/12/a-new-colormap-for-matlab-part-3-some-reactions

https://eagereyes.org/basics/rainbow-color-map

http://medvis.org/2012/08/21/rainbow-colormaps-what-are-they-good-for-absolutely-nothing/

Watch the video on this page for a really good explanation:

https://bids.github.io/colormap/

[Jesse]

This is my new code, the colors seem to work, but not as i expected. And also my subplot is gone... how to deal with this?

figure;
subplot(211)
semilogx(freqs,Y)
cmap = colormap(jet(size(vars,2)));
cmap = cmap(randperm(length(cmap)),:)
ax = axes('colororder',cmap);
hold on;
if isequal(afstand,'alle')
else
    title({['Afstand ',afstand, ' - node ',node]});
end
xlabel('frequentie [Hz]')
ylabel('trillingssnelheid(rms) [mm/s]')
legend(vars)
grid on;
hold on;
axis tight;
xlim([0 100])
ylim([0 0.000040])

subplot(212)
plot(time,data_time(:,1:1:end))  % je kan ook een aantal lijnen plotten bijv. [1:5:7]
cmap = colormap(jet(size(vars,2)));
cmap = cmap(randperm(length(cmap)),:)
ax = axes('colororder',cmap);
hold on;
plot(time,data_time)

legend(unique(vars))
grid on;
axis tight;
hold on;

[Image Analyst]

Can you attach 'Y:\Geovib\08\matlab.mat' with the paper clip icon, so people can run and improve your code?

[Jesse]

No problem, here it is.

[jonas]

Fixed code in the attachments. Note that I have changed to the default colormap (parula) and commented out the color randomization, so now you get a nice color gradient. I'd suggest you only display a single legend, as they are identical.

It does seem like you actually have three variables, so you could plot this using scatter and assign colors automatically from the third variable (units in [m]). If you did that, then you could skip the legend and just add a colorbar instead. Unfortunately I do not think MATLAB has a built in lineplot where the color is connected to a third variable (please someone correct me if I'm wrong) but there are various FEX functions (like this )

[Jesse]

Thank you very much! That's the answer i was looking for. Now i can apply this to all my plots. Thanks!