Legend inside for loop

Hello,

I want to generate single legend outside for the figure window for all subplots. I am doing plots inside a loop like this:

t,x and y are given datas

for i=1:10
    figure()
    subplot(2,2,i)
    plot(x,y)
    hold on
    plot(t,y)
    subplot(2,2,i)
    plot(x,y-y')
    hold on
   %  ........
    legend('1','2,','3')
end

But i am still getting the legend on all plots.

any help is appreciated

Dan

[Adam Danz]

This should produce an error since it appears that you are attempting to generate 10 suplots in a 2x2 grid. But since we don't see the rest of what's going on within the loop, I can't be sure.

It's unclear what the goals is and what the actual results are.

[danel james]

sorry it shoud be (2,5,i) and end is followed

Can you kindly share sample code for this case? thank you dear

[Adam Danz]

I must have missed the end. Thanks.

[Adam Danz]

Move figure out of the loop if you want all suplots within the same figure.

Move Legend out of the loop if you only want to create a legend for the last subplot.

[KSSV]

Refer this: https://in.mathworks.com/matlabcentral/answers/98474-is-there-a-command-in-matlab-for-creating-one-overall-legend-when-i-have-a-figure-with-subplots

[danel james]

Unfortunatley this method is not working for me, dear KSSV

Answer 1

[Walter Roberson]

for i=1:10
    figure()
    subplot(2,2,i)
    H(3*i-2) = plot(x, y, 'displayname', i + "A");
    hold on
    H(3*i-1) = plot(t, y, 'displayname', i + "B");
    subplot(2,2,i)
    H(3*i) = plot(x, y-y', 'displayname', i + "C");
    hold on
   %  ........
end
legend(H)

Are you wanting only 3 entries in the legend, total? If so then you would want to be explicit about the line colors, and you would legend(H(1:3))

[danel james]

I have to use get 10 plots and i am using subplot(2,5,i) .

thank you

[Walter Roberson]

for i=1:10
    subplot(2,5,i)
    H(3*i-2) = plot(x, y, 'displayname', i + "A");
    hold on
    H(3*i-1) = plot(t, y, 'displayname', i + "B");
    H(3*i) = plot(x, y-y', 'displayname', i + "C");
    hold off
   %  ........
end
legend(H)

[danel james]

I used your code to modify mine and its giving me this :

Error using legend (line 272)

Invalid argument. Type 'help legend' for more

information.

Error in single_legend (line 122)

legend(H)

[Walter Roberson]

x = 1:10; y = rand(size(x));
for i=1:10
    subplot(2,5,i)
    H(3*i-2) = plot(x, y, 'displayname', i + "A");
    hold on
    H(3*i-1) = plot(x, y, 'displayname', i + "B");
    H(3*i) = plot(x, y-y', 'displayname', i + "C");
    hold off
   %  ........
end

Unable to perform assignment because the left and right sides have a different number of elements.

legend(H)

What size is y? If y is a vector then y - y' creates a square matrix in which each element of y is subtracted from each other element of y; the result of plotting that would be multiple lines.