Selecting a point on a scatter plot, saving index of point

What is the best way to allow a user to select 5 data points on a scatter plot and then save the index of these plots?

Code I am currently using:

disp('Following the trajectory from <start> to <end>, please click 5 points on the plot where you think the keypress moments are, press Enter to confirm');
% Save points selected on plot by user
[user_selected_keypressframes] = ginput;

% Extract coordinates for each user selected point and save
[uskf1] = user_selected_keypressframes(1,:);
[uskf2] = user_selected_keypressframes(2,:);
[uskf3] = user_selected_keypressframes(3,:);
[uskf4] = user_selected_keypressframes(4,:);
[uskf5] = user_selected_keypressframes(5,:);

Issue:

This code allows the user to click/select any area within the plot, I want them to only be able to click/select data points so I can save the index of these points.

[Walter Roberson]

Sounds like you might want brushing https://www.mathworks.com/help/matlab/ref/brush.html

Answer 1

[darova]

You can use pdist2() and min() functions to select closest to your data points

clc,clear

x = linspace(0,10,20)';
y = sin(x);
plot(x,y,'.-b')

g = ginput(3);                 % pick 3 points
D = pdist2([x y],g);
[~,ix] = min(D);               % indices

hold on
plot(x(ix),y(ix),'or')
hold off

[James Morris]

This has worked perfectly for me, top answer.

[darova]

♥