Legend in bar3 in MATLAB - 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 cores 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 e.g. 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'});