How to change line and marker style in a legend?

My script generates a composite plot, made of dozens of lines and line segments. I am trying to add a custom legend to the plot, which contains just 3 of those lines, but I don't seem to be able to control the style of the lines and markers in that legend.

The plot looks like this:

In the legend, I want Line1 style to be 'b.-', Line2 style to be 'r-o' and Line3 style to be 'g-o'.

Is there a way to define a legend with a set number of labels and specific line styles?

You can achieve this using the 'HandleVisibility' property of the plots, which controls whether they appear in the legend or not.

Since you don't provide an example graph in your code (please do it next time), let's create one:

t = linspace(0,1,30);
hold on, grid on
styles = {'b.-', 'r-o', 'g-o'};
for k = 1:12
    plot(t, cos(pi/3*t+(k-1)/14*2*pi).*(1-t).^2, styles{mod(k-1,3)+1}, 'linewidth', .8)
end

Then, all you have to do is:

• prevent all plots from appearing in the legend by setting their 'HandleVisibility' property to 'off';
• create fake plots with with the desired styles for the legend. The plots contain NaN values, so they won't show on the graph.

set(get(gca, 'children'), 'HandleVisibility', 'off') % existing plots: not in legend
legend_styles = {'b.-', 'r-o', 'g-o'};
legend_texts = {'Line1', 'Line2', 'Line3'};
hold on % make sure existing plots are kept
for p = 1:numel(legend_styles)
    plot(NaN, legend_styles{p}); % fake plot for legend
end
legend(legend_texts{:})