display a shared legend for bar graph

Hi all,

I want to display a shared legend for a bar graph. I have tried a few things but they didn't work out. Could anyone please help? I really appreciate your support. Please find the code below.

Thanks

P_g1(1,:) =  [7.8269 5.8145 0.5642+0.0030 0.1352];
P_g1(2,:) =  [7.8612 5.7935 0.5371+0.0024 0.2280];
P_g1(3,:) =  [7.8815 5.7321 0.5095+0.0020 0.3433];
P_g1(4,:) =  [7.8750 5.6529 0.4718+0.0017 0.4496];

P_g2(1,:) =  [7.8034 5.7474 0.3709+0.0019 0.3708];
P_g2(2,:) =  [7.8572 5.9635 0.4167+0.0015 0.1771];
P_g2(3,:) =  [7.8758 6.0315 0.4243+0.0013 0.1223];
P_g2(4,:) =  [7.7865 6.0026 0.4204+0.0012 0.1422];
sl = [240:20:300];
%% 
figure
t = tiledlayout('flow','TileSpacing','compact');
nexttile
b = bar(sl,P_g1,0.9);
set(b, {'DisplayName'}, {'Accepted power','Absorbed power','Losses','Radiating power'}')
ax=gca;
ax.TickLabelInterpreter = 'latex';
axis tight
ylim([0 8])
grid on
ylabel('Power (W)','Interpreter','Latex')
xlabel('Shield length (mm)','Interpreter','Latex')
title('$\gamma_1$','Interpreter','Latex')
%h = legend('Location','eastoutside');
%set(h,'Interpreter','Latex')
set(gcf,'Color','w')
set(findall(gcf,'-property','FontName'),'fontsize',18)
nexttile
b = bar(sl,P_g2,0.9);
set(b, {'DisplayName'}, {'Accepted power','Absorbed power','Losses','Radiating power'}')
ax=gca;
ax.TickLabelInterpreter = 'latex';
axis tight
ylim([0 8])
grid on
ylabel('Power (W)','Interpreter','Latex')
xlabel('Shield length (mm)','Interpreter','Latex')
title('$\gamma_2$','Interpreter','Latex')
%h = legend('Location','eastoutside');
%set(h,'Interpreter','Latex')
set(gcf,'Color','w')
set(findall(gcf,'-property','FontName'),'fontsize',18)
nexttile
set(b, {'DisplayName'}, {'Accepted power','Absorbed power','Losses','Radiating power'}')
h = legend;
h.Layout.Tile = 'east';

[dpb]

You write over your various figure handles so there's no access to any but the latest -- just as a side point.

What, effect, specifically, are you trying to achieve, in other words, what does "a shared legend" mean to you?

[Shan Chu]

Hi, Thanks for your comment. Basically, the two bar graphs have the same legend like in this picture. So I think it would be nicer to have a shared legend. I tried to follow one example in the section: "Display Shared Legend in Tiled Chart Layout" (https://uk.mathworks.com/help/matlab/ref/legend.html)

But it doesn't work for bar graphs.

Thanks

Answer 1

[Dave B]

There's an extraneous call to nexttile at the bottom, but after removing that I see what I'd call a shared legend....can you help me understand what's missing? (or is this what you were expecting)

P_g1(1,:) =  [7.8269 5.8145 0.5642+0.0030 0.1352];
P_g1(2,:) =  [7.8612 5.7935 0.5371+0.0024 0.2280];
P_g1(3,:) =  [7.8815 5.7321 0.5095+0.0020 0.3433];
P_g1(4,:) =  [7.8750 5.6529 0.4718+0.0017 0.4496];
P_g2(1,:) =  [7.8034 5.7474 0.3709+0.0019 0.3708];
P_g2(2,:) =  [7.8572 5.9635 0.4167+0.0015 0.1771];
P_g2(3,:) =  [7.8758 6.0315 0.4243+0.0013 0.1223];
P_g2(4,:) =  [7.7865 6.0026 0.4204+0.0012 0.1422];
sl = [240:20:300];
%% 
figure
t = tiledlayout('flow','TileSpacing','compact');
nexttile
b = bar(sl,P_g1,0.9);
set(b, {'DisplayName'}, {'Accepted power','Absorbed power','Losses','Radiating power'}')
ax=gca;
ax.TickLabelInterpreter = 'latex';
axis tight
ylim([0 8])
grid on
ylabel('Power (W)','Interpreter','Latex')
xlabel('Shield length (mm)','Interpreter','Latex')
title('$\gamma_1$','Interpreter','Latex')
%h = legend('Location','eastoutside');
%set(h,'Interpreter','Latex')
set(gcf,'Color','w')
set(findall(gcf,'-property','FontName'),'fontsize',18)
nexttile
b = bar(sl,P_g2,0.9);
set(b, {'DisplayName'}, {'Accepted power','Absorbed power','Losses','Radiating power'}')
ax=gca;
ax.TickLabelInterpreter = 'latex';
axis tight
ylim([0 8])
grid on
ylabel('Power (W)','Interpreter','Latex')
xlabel('Shield length (mm)','Interpreter','Latex')
title('$\gamma_2$','Interpreter','Latex')
%h = legend('Location','eastoutside');
%set(h,'Interpreter','Latex')
set(gcf,'Color','w')
set(findall(gcf,'-property','FontName'),'fontsize',18)
%nexttile
set(b, {'DisplayName'}, {'Accepted power','Absorbed power','Losses','Radiating power'}')
h = legend;
h.Layout.Tile = 'east';

[Shan Chu]

Oh, This is amazing. Thank you sir. So just remove the nexttile at the end. I thought the legend needs to be in a tile. So silly me :D

[Dave B]

Glad it helps!

Actually legend does need to be in a tile! (it's the 'east' tile)

I think what happened was you called nexttile, and legend defaults to grabbing its data from the current axes, so you were making a legend that went with an empty axes.