Skip legend with empty line

Question

Zheng Liu 2018-1-10

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/376508-skip-legend-with-empty-line

评论： Star Strider 2018-11-20

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!

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Answer 1

Star Strider 2018-1-10

2
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/376508-skip-legend-with-empty-line#answer_299508

在 MATLAB Online 中打开

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')