Legend colors match with plot

Hi. I have a for loop in which I plot some curves with different colors.

P=[0.25 0.25 0.2 0.15 0.15];
color = {'r','c','g','y','b','m','k'};
for i=1:numel(P)
        plot(1:N,nElemMat(:,i),color{i}); yline(P(i)); hold on; 
end   

I would like to have a legend in which each color represent the correspondent P(i) (red -> 0.25 , cyan -> 0.25, green -> 0.20,...).

I tried with

legend('0.25', '0.25', '0.2','0.15','0.15');

but colors don't match and I'm not using P.

Do you have any suggestion? Thanks

Answer 1

[the cyclist]

Here is one way to code this (assuming I understand what you meant):

rng default
N = 3;
P=[0.35 0.25 0.2 0.15 0.10];
nElemMat = rand(N,numel(P));
color = {'r','c','g','y','b','m','k'};

figure
hold on
for i=1:numel(P)
    plot(1:N,nElemMat(:,i),color{i})
    hy(i) = yline(P(i));
    set(hy(i),'Color',color{i})
end
legend(hy,color)

Warning: Ignoring extra legend entries.

The code changes I made were

• Assign a handle to each yline, so that I could assign the color to each one. (This is the main thing you wanted.)
• Create the figure explicitly, and execute hold on just once.
• Define variables that you didn't have in your code, so I had a piece of self-contained code that would run.
• Changed the values of P, so you see every line

[Rosario Frontino]

Thanks for your answer and the explanation. My main problem is the legend for the plot.

I would like to have a legend in the form (P(i) -> color(i)). Is it possible?

[the cyclist]

Sorry, I missed the part about a legend.

I've edited the code to show how to use the handles as an input to legend.

Note that the my code here is a bit weird, because I am using the handles to the horizontal lines, not to the plot lines themselves (but you seem to have a one-to-one correspondence, so that is OK). You could also have assigned handles to the plot lines themselves instead:

hp(i) = plot(...)

and assigned a legend based on those. That would be the norm, actually.

Also, I just used the color names themselves as the legend text. Obviously, you don't need to do that.