How can I add an automatic legend to a graph with 10+ lines?

I'm trying to generate a graph that has potentially 50 lines on it. In terms of formatting, I only know of the command "legend('Title 1''Title 2'....'Title n'). Given the number of lines I need to plot, I was wondering if there was a way to generate these titles automatically so if I increase the number of lines I don't have to manually add more titles in the legend.

Answer 1

[Dev]

Hi John,

We can automate the generation of legend titles for any given number of lines using a ‘for’ loop which iterates over the total number of lines we want to plot. To do so, we can create a cell array and loop over the same to store each title as a cell in this array. For more information on creating and working with cell arrays, kindly refer to the below documentation-

https://www.mathworks.com/help/matlab/cell-arrays.html

To store the title in each cell, we can use the ‘sprintf’ function in MATLAB. More details on the same can be referred below-

https://www.mathworks.com/help/matlab/ref/string.sprintf.html

For further reference, below is a dummy code snippet which helps add legend titles to a graph having 10 lines (can be customized using the variable ‘n’).

% No. of lines to plot
n = 10;

figure;
% Hold the plot to overlay all lines
hold on;

% Generate and plot the lines
for i = 1:n
    % Plot each line with some random data (replace this with actual data)
    plot(rand(1, 10));  % Replace with your data or plotting function
end

% Automatically generate legend titles
legendLabels = cell(1, n);  % Cell array to hold the legend labels

for i = 1:n
    legendLabels{i} = sprintf('Title %d', i);  % Automatically generate titles like 'Title 1', 'Title 2', etc.
end

% Set the legend
legend(legendLabels);

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In the code above, we provide the titles stored in the ‘legendLabels’, which is a cell array, to the legend function which shows the titles for all 10 plotted lines, please refer to the code output above for your reference.

I hope this matches your expectations.