group of lines with the same color (legend)

i have two groups of lines, one group in blue (4 lines) and the second in red (3 lines) at the same plot. i want to create a legend with two labels - one for the blue group and the second for the red group, i can't find a function to do so. the only thing that i manage to do is to write 7 labels, and then i get label for each line but it looks stupid. i want to have only two labels for each group.

thanks

[Socrates - Athanasios Kotronakos]

Hey! Could you share how you did it? Thank you

Answer 1

[Walter Roberson]

You can record the handles of the lines, and only pass in one of the red group and one of the blue group to legend. For example,

h1 = plot(x, first_y, 'b');     %first_y has 4 columns so h1 is length 4
h2 = plot(x, second_y, 'r');    %second_y has 3 columns so h2 is length 3
legend([h1(1), h2(1)], 'Blue Meanies', 'Red Rovers')

[Benjamin Schafer]

Is this still working with later versions of Matlab? The new legend command in Matlab 2018 (at least when I am runing into it) seems to want to be smart and list all lines no matter what I do with the handles. I found some gitHub threads - but man the new legend command is totally different than my workflow before which was very much like this example.

Answer 2

[Taniel Winner]

Use this function I found extremely helpful and easy to use in my code.

https://www.mathworks.com/matlabcentral/fileexchange/67646-legendunq

[Adam Danz]

Thanks, Taniel. I've edited your comment to convert the URL to a link.