Color of legend does't change in the loop.

Hi guys

Please run this simple code:

syms x z;
for i=1:2
    z=[x,0];
    fplot(z(1,1),[i i+1] , 'r');
    title('z(x)');
    hold on;
end
for j=1:2
    z=[-x,0];
    fplot(z(1,1),[j j+1] , 'b');
    title('z(x)');
    legend('one' , 'two');
    hold on;
end

Why the legend color is red for 'two' ?

I defined blue for it. Can someone help here please?

Thank you.

[KSSV]

It is because, the first loop plots in red color.

Answer 1

[Rik]

Each call to fplot will create a line object. So in your code you create 4 objects, but you provide only 2 legend entries.

syms x z;
plot_handles=[];
for i=1:2
    z=[x,0];
    plot_handles(i)=fplot(z(1,1),[i i+1] , 'r');
    hold on;
end
for j=1:2
    z=[-x,0];
    plot_handles(i+j)=fplot(z(1,1),[j j+1] , 'b');
    hold on;
end
title('z(x)');
legend(plot_handles([1 3]),{'one' , 'two'});