Legend in a bar plot in Matlab

问题

How can I plot a legend in a bar plot in Matlab? Here is the code:

Y = [1.5056
0.72983
3.4530
3.2900
1.4839
12.9 ];
n = length(Y);
h = bar(Y);
colormap(summer(n));
grid on

l = cell(1,6);
l{1}='L'; l{2}='B'; l{3}='R'; l{4}='P'; l{5}='h'; l{6}='Ri';    
legend(h,l);

This give an error: Warning: Ignoring extra legend entries. I tried solutions which I found on the SO and web, but I couldn't resolve this.

回答1:

Instead of legend, you can solve it using the tick labels for example:

set(gca,'xticklabel', l) 

This will label each bar. If you want to use legend you need to have a matrix data, so the bar plot will show several bars per entry. For example

Y=rand(10,6)
h = bar(Y);
colormap(summer(n));
grid on
l = cell(1,6);
l{1}='L'; l{2}='B'; l{3}='R'; l{4}='P'; l{5}='h'; l{6}='Ri';    
legend(h,l);

Or, you can use different bar() calls in this way:

h = bar(diag(Y));

But then you'll get a displacement per each bar:

So, the only way really to do that using legend is to plot each bar seperatly, similar to what is discussed here.

回答2:

Further to bla's answer, you can use

h = bar(diag(Y),'stacked');

if you want to avoid the displacement.

来源：https://stackoverflow.com/questions/14697525/legend-in-a-bar-plot-in-matlab