Legend with multiple colors for a single bar plot

I have a single bar plot and i have managed to color the bars in 3 different colors. When I try to create a legend, it does only show one color. How can i add the two other colors to the legend when i only have one bar plot?

My code looks like this:

figure(2)
bar_h = bar(T_orderO);
title('Tid brugt på hvert spørgsmål')
xlabel('Spørgsmålsnummer')
ylabel('Tid (s)')
set(gca,'XLim',[0 numel(O)+1])
set(gca,'xticklabel',O)
set(gca,'XTick',1:1:numel(O))
set(gca,'YLim',[0 max(T_orderO)*1.1])
%set(gca,'YTick',0:max(T_orderO)+1)
hbar_child = get(bar_h, 'Children');
set(hbar_child,'CData',T_orderO);
set(hbar_child,'CDataMapping','direct');
index = 1:numel((R_orderO));
for i = 1:length(R_orderO)
      if R_orderO(i) == -1
          index(i) = 1;       
      elseif R_orderO(i) == 1
          index(i) = 2;
      else
          index(i) = 3;
      end
end
mycolor=[1 0 0; 0 1 0; 1 1 1];
colormap(mycolor);
set(hbar_child, 'CData',index);

Answer 1

[Michael Haderlein]

Hi Kenneth,

I don't know if that's what you'd like to have, but I have used "invisible" plots to generate "artificial" legend entries. Just plot only one data point and set it to NaN:

figure, hold all
plot(1,nan,'k-') %legend entry 1
plot(1,nan,'ko') %legend entry 2
legend('Experiment','Simulation')

%actual data plots  
plot(1:4,rand(1,4),'b-')
plot(1:4,rand(1,4),'bo')
plot(1:4,rand(1,4)+1,'r-')
plot(1:4,rand(1,4)+1,'ro')
plot(1:4,rand(1,4)+2,'g-')
plot(1:4,rand(1,4)+2,'go')
plot(1:4,rand(1,4)+3,'c-')
plot(1:4,rand(1,4)+3,'co')

That should be possible with bar plots, too.

Michael

[Kenneth]

Hi Michael,

That was exactly what I wanted, and it works fine with bar plots too. Thanks a lot.

Kenneth

[Giuseppe Degan Di Dieco]

Dear Michael,

your solution it's still useful in 2021!

Thanks for your help.

Best!