How to create an overall legend for subplots with the SUBAXIS function?

Hi, how can I create an overall legend by using the subaxis function?

The following example does not work:

x = -10:10;
city = {'London', 'Paris', 'Berlin','Madrid'};
season = {'summer','winter'};
colors  = {'blue','red','black','magenta'};

for i = 1 : 4
    subaxis(2,2,i);
    y1 = (rand(1,21)-0.5)*20;
    y2 = (rand(1,21)-0.5)*10;
    hold on
    p1(i) = plot(x, y1, 'Color', colors{i}, 'LineStyle','--');
    p2(i) = plot(x, y2, 'Color', colors{i}, 'LineStyle','-');
    hold off
    p1(i).DisplayName = [city{i} ', ' season{1}];
    p2(i).DisplayName = [city{i} ', ' season{2}];
 
end

lgd = legend;
lgd.Position = 'northeastoutside';

Answer 1

[Matt J]

x = -10:10;
city = {'London', 'Paris', 'Berlin','Madrid'};
season = {'summer','winter'};
colors  = {'blue','red','black','magenta'};

for i = 1 : 4
    ax(i)=subaxis(2,2,i);
    y1 = (rand(1,21)-0.5)*20;
    y2 = (rand(1,21)-0.5)*10;
    hold on
    p1(i) = plot(x, y1, 'Color', colors{i}, 'LineStyle','--');
    p2(i) = plot(x, y2, 'Color', colors{i}, 'LineStyle','-');
    hold off
    p1(i).DisplayName = [city{i} ', ' season{1}];
    p2(i).DisplayName = [city{i} ', ' season{2}];
 
end

for i=1:4
 ax(i).Position([1,3])=ax(i).Position([1,3])*0.8; %make room for legend
end

lgd = legend;
lgd.Position(1:2)=[0.75,0.4];

[Sim]

Thanks a lot @Matt J !!

However, in my real case (a bit diffirent from this example I posted here), I still see the original "frames" of the subplots as thin rectanglular black lines (are they the "axes profiles" maybe?) .... How can I remove them ?

[Matt J]

I don't have a clear picture of what you're seeing. Maybe try clearing and/or resizing the figure.

[Sim]

Oh, solved..!!

Your solution works well, I just had an annotation, and the "EdgeColor" of the annotation was still "black" (the default color)....

I solved it just by setting "EdgeColor" as "none", as shown here:

annotation('textbox','String',str,...
           'Position',ax(i).Position,...
           'EdgeColor','none');