How do I fill legend on double y axis plot?

I have a double y axis plot and I have 3 curves on the left axis and 1 on the right. When I add the legend to the plot I can fill out the legend tag for the first 3 curves, but when I try to add the fourth entry an error appears that says there are extra entries. How do I add the tag for the right axis into the legend?

Answer 1

[Star Strider]

Without seeing your code (and your MATLAB version, although I’m not certain how relevant that is in this instance), it’s not possible to determine precisely what the problem is.

Using the 'DisplayName' property works here —

t = linspace(0, 1, 250);
y = sin([1;3;5;7]*2*pi*t);

figure
yyaxis left
hold on
for k = 1:3
    hpl(k) = plot(t, y(k,:), 'DisplayName',"Curve "+k);
end
hold off
yyaxis right
hpr = plot(t, y(4,:), 'DisplayName',"Curve "+4);
legend('Location','best')

I added the plot handles in case it’s necessary to pass them as the first argument to the legend call, although that’s not necessary here. It may be necessary for you to use them, so I included them.

.