MATLAB: Skip legend with empty line

figurelegendplotting

Hi folks,
I found specifying Matlab legend confusing when I have a line that could be empty (then has an empty handle). I want to skip the legend for empty line. For example:
h1 = plot([]);      % Blue line

hold on;
h2 = plot(rand(1,10),'r');  % Red line

h3 = plot(rand(1,10),'g');  % Green line

legend([h1 h2 h3],{'want to withdraw this if line unexist', 'hello', 'world'});
In this case, the legend for h1 will be assigned on h2, and the legend for h3 will be ignored.
Do you have any better solution rather than doing (since I might have different lines empty or not, and I just want the matched legends):
h1 = plot([]);      % Blue line
hold on;
h2 = plot(rand(1,10),'r');  % Red line
h3 = plot(rand(1,10),'g');  % Green line
if ~isempty(h1)
  legend([h1 h2 h3],{'want to skip this if line unexist', 'hello', 'world'})
else
  legend([h2 h3],{'hello', 'world'})
end
Thanks!

Best Answer

Try this:
h1 = plot([], 'DisplayName','want to withdraw this if line unexist');      % Blue line
hold on;
h2 = plot(rand(1,10),'r', 'DisplayName','hello');  % Red line
h3 = plot(rand(1,10),'g', 'DisplayName','world');  % Green line
legend('show')
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