How can I identify which line in a figure I am clicking on?

I am plotting 1000 lines on a plot and what to identify which line is the outlier is.

Answer 1

[Jan]

You can use the ButtonDownFcn of the lines:

y        = rand(10, 10);
LineList = plot(1:10, y);
set(LineList, 'ButtonDownFcn', {@myLineCallback, LineList});

function myLineCallback(LineH, EventData, LineList)
disp(LineH);                    % The handle
disp(get(LineH, 'YData'));      % The Y-data
disp(find(LineList == LineH));  % Index of the active line in the list
set(LineList, 'LineWidth', 0.5);
set(LineH,    'LineWidth', 2.5);
uistack(LineH, 'top');  % Set active line before all others

I've inserted some ideas about what "identify" could mean: The line's handle, the YData or the index related to all lines.

[Chang hsiung]

Great, thanks a lot

[Philip]

I also tried it and found that it works!

I might also just add an additional useful tip for the question posed. If you're plotting in a for-loop, you can give each line a name using the DisplayName argument inside your plot function. Example:

for i=1:length(numPlots)

plotObject(i) = plot(myPlotXaxis(i),myPlotYaxis(i),DisplayName='IterationNum-'+string(i))

set(p1(i), 'ButtonDownFcn', {@myLineCallback, p1(i)});

end

In this way, each line will have a specific name. This will come up in the command line, when you click on one of the lines on your graph.