Legend in bar3 in MATLAB

Question

I can't figure out how to create the legends (for colors) in the attached code?

test1=[5 10 7;
    1 100 0;
    1 3 2];

test2=[10 15 10;
    10 80 10;
    5 5 15];

test3=[10 10 10;
    20 200 20;
    30 10 30];

core=bar3(test1);
set(core,'FaceColor',[1 0 0]); %red
for i=1:length(core)
    zz=get(core(i),'Zdata');
    k=1;
    for j= 0:6:(6*length(core)-6)
        zz(j+1:j+6,:)=zz(j+1:j+6,:)+test2(k,i);
        k=k+1;
    end
    set(core(i),'Zdata',zz);
end
hold on
core=bar3(test2);
set(core,'FaceColor',[0 1 1]);%cyan
hold off
for i=1:length(core)
    zz=get(core(i),'Zdata');
    k=1;
    for j= 0:6:(6*length(core)-6)
        zz(j+1:j+6,:)=zz(j+1:j+6,:)+test3(k,i);
        k=k+1;
    end
    set(core(i),'Zdata',zz);
end
hold on
core=bar3(test3);
set(core,'FaceColor',[1 1 0]);%yellow
hold off

Answer 1

First, I would rename all core s to core1 , core2 and core3 to correspond to test1 , test2 and test3 , and also not to override the handles. Then, if you check the size of each of these using eg size(core1) , you will see that each of these contains 3 handles to 3 plots. All 3 have the same color, so you can just pick one handle and supply it to the legend as a first argument. So at the end you just need to add

legend([core1(1) core2(1) core3(1)], {'A', 'B', 'C'});

The full code

test1=[5 10 7;
    1 100 0;
    1 3 2];

test2=[10 15 10;
    10 80 10;
    5 5 15];

test3=[10 10 10;
    20 200 20;
    30 10 30];

core1=bar3(test1);
set(core1,'FaceColor',[1 0 0]); %red
for i=1:length(core1)
    zz=get(core1(i),'Zdata');
    k=1;
    for j= 0:6:(6*length(core1)-6)
        zz(j+1:j+6,:)=zz(j+1:j+6,:)+test2(k,i);
        k=k+1;
    end
    set(core1(i),'Zdata',zz);
end
legend({'A'});
hold on
core2=bar3(test2);
set(core2,'FaceColor',[0 1 1]);%cyan
hold off
for i=1:length(core2)
    zz=get(core2(i),'Zdata');
    k=1;
    for j= 0:6:(6*length(core2)-6)
        zz(j+1:j+6,:)=zz(j+1:j+6,:)+test3(k,i);
        k=k+1;
    end
    set(core2(i),'Zdata',zz);
end
hold on
core3=bar3(test3);
set(core3,'FaceColor',[1 1 0]);%yellow
hold off

legend([core1(1) core2(1) core3(1)], {'A', 'B', 'C'});